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rfc:rfc4005

Network Working Group P. Calhoun Request for Comments: 4005 G. Zorn Category: Standards Track Cisco Systems Inc.

                                                             D. Spence
                                                            Consultant
                                                             D. Mitton
                                                     Circular Networks
                                                           August 2005
             Diameter Network Access Server Application

Status of This Memo

 This document specifies an Internet standards track protocol for the
 Internet community, and requests discussion and suggestions for
 improvements.  Please refer to the current edition of the "Internet
 Official Protocol Standards" (STD 1) for the standardization state
 and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

 Copyright (C) The Internet Society (2005).

Abstract

 This document describes the Diameter protocol application used for
 Authentication, Authorization, and Accounting (AAA) services in the
 Network Access Server (NAS) environment.  When combined with the
 Diameter Base protocol, Transport Profile, and Extensible
 Authentication Protocol specifications, this application
 specification satisfies typical network access services requirements.
 Initial deployments of the Diameter protocol are expected to include
 legacy systems.  Therefore, this application has been carefully
 designed to ease the burden of protocol conversion between RADIUS and
 Diameter.  This is achieved by including the RADIUS attribute space
 to eliminate the need to perform many attribute translations.
 The interactions between Diameter applications and RADIUS specified
 in this document are to be applied to all Diameter applications.  In
 this sense, this document extends the Base Diameter protocol.

Calhoun, et al. Standards Track [Page 1] RFC 4005 Diameter Network Access Server Application August 2005

Table of Contents

 1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  5
     1.1.  Terminology  . . . . . . . . . . . . . . . . . . . . . .  5
     1.2.  Requirements Language  . . . . . . . . . . . . . . . . .  6
     1.3.  Advertising Application Support  . . . . . . . . . . . .  6
 2.  NAS Calls, Ports, and Sessions . . . . . . . . . . . . . . . .  6
     2.1.  Diameter Session Establishment . . . . . . . . . . . . .  7
     2.2.  Diameter Session Reauthentication or Reauthorization . .  7
     2.3.  Diameter Session Termination . . . . . . . . . . . . . .  8
 3.  NAS Messages . . . . . . . . . . . . . . . . . . . . . . . . .  9
     3.1.  AA-Request (AAR) Command . . . . . . . . . . . . . . . .  9
     3.2.  AA-Answer (AAA) Command  . . . . . . . . . . . . . . . . 11
     3.3.  Re-Auth-Request (RAR) Command  . . . . . . . . . . . . . 13
     3.4.  Re-Auth-Answer (RAA) Command . . . . . . . . . . . . . . 14
     3.5.  Session-Termination-Request (STR) Command  . . . . . . . 15
     3.6.  Session-Termination-Answer (STA) Command . . . . . . . . 15
     3.7.  Abort-Session-Request (ASR) Command  . . . . . . . . . . 16
     3.8.  Abort-Session-Answer (ASA) Command . . . . . . . . . . . 17
     3.9.  Accounting-Request (ACR) Command . . . . . . . . . . . . 17
     3.10. Accounting-Answer (ACA) Command. . . . . . . . . . . . . 19
 4.  NAS Session AVPs . . . . . . . . . . . . . . . . . . . . . . . 20
     4.1.  Call and Session Information . . . . . . . . . . . . . . 21
     4.2.  NAS-Port AVP . . . . . . . . . . . . . . . . . . . . . . 22
     4.3.  NAS-Port-Id AVP  . . . . . . . . . . . . . . . . . . . . 22
     4.4.  NAS-Port-Type AVP  . . . . . . . . . . . . . . . . . . . 22
     4.5.  Called-Station-Id AVP  . . . . . . . . . . . . . . . . . 23
     4.6.  Calling-Station-Id AVP . . . . . . . . . . . . . . . . . 23
     4.7.  Connect-Info AVP . . . . . . . . . . . . . . . . . . . . 24
     4.8.  Originating-Line-Info AVP  . . . . . . . . . . . . . . . 24
     4.9.  Reply-Message AVP  . . . . . . . . . . . . . . . . . . . 25
 5.  NAS Authentication AVPs  . . . . . . . . . . . . . . . . . . . 26
     5.1.  User-Password AVP  . . . . . . . . . . . . . . . . . . . 26
     5.2.  Password-Retry AVP . . . . . . . . . . . . . . . . . . . 27
     5.3.  Prompt AVP . . . . . . . . . . . . . . . . . . . . . . . 27
     5.4.  CHAP-Auth AVP  . . . . . . . . . . . . . . . . . . . . . 27
     5.5.  CHAP-Algorithm AVP . . . . . . . . . . . . . . . . . . . 28
     5.6.  CHAP-Ident AVP . . . . . . . . . . . . . . . . . . . . . 28
     5.7.  CHAP-Response AVP  . . . . . . . . . . . . . . . . . . . 28
     5.8.  CHAP-Challenge AVP . . . . . . . . . . . . . . . . . . . 28
     5.9.  ARAP-Password AVP  . . . . . . . . . . . . . . . . . . . 28
     5.10. ARAP-Challenge-Response AVP. . . . . . . . . . . . . . . 28
     5.11. ARAP-Security AVP. . . . . . . . . . . . . . . . . . . . 29
     5.12. ARAP-Security-Data AVP . . . . . . . . . . . . . . . . . 29
 6.  NAS Authorization AVPs . . . . . . . . . . . . . . . . . . . . 29
     6.1.  Service-Type AVP . . . . . . . . . . . . . . . . . . . . 30
     6.2.  Callback-Number AVP  . . . . . . . . . . . . . . . . . . 32
     6.3.  Callback-Id AVP  . . . . . . . . . . . . . . . . . . . . 32

Calhoun, et al. Standards Track [Page 2] RFC 4005 Diameter Network Access Server Application August 2005

     6.4.  Idle-Timeout AVP . . . . . . . . . . . . . . . . . . . . 32
     6.5.  Port-Limit AVP . . . . . . . . . . . . . . . . . . . . . 32
     6.6.  NAS-Filter-Rule AVP  . . . . . . . . . . . . . . . . . . 32
     6.7.  Filter-Id AVP  . . . . . . . . . . . . . . . . . . . . . 33
     6.8.  Configuration-Token AVP  . . . . . . . . . . . . . . . . 33
     6.9.  QoS-Filter-Rule AVP  . . . . . . . . . . . . . . . . . . 33
     6.10. Framed Access Authorization AVPs . . . . . . . . . . . . 35
           6.10.1.  Framed-Protocol AVP . . . . . . . . . . . . . . 35
           6.10.2.  Framed-Routing AVP. . . . . . . . . . . . . . . 35
           6.10.3.  Framed-MTU AVP. . . . . . . . . . . . . . . . . 35
           6.10.4.  Framed-Compression AVP. . . . . . . . . . . . . 36
     6.11. IP Access Authorization AVPs.. . . . . . . . . . . . . . 36
           6.11.1.  Framed-IP-Address AVP . . . . . . . . . . . . . 36
           6.11.2.  Framed-IP-Netmask AVP . . . . . . . . . . . . . 36
           6.11.3.  Framed-Route AVP. . . . . . . . . . . . . . . . 37
           6.11.4.  Framed-Pool AVP . . . . . . . . . . . . . . . . 37
           6.11.5.  Framed-Interface-Id AVP . . . . . . . . . . . . 37
           6.11.6.  Framed-IPv6-Prefix AVP. . . . . . . . . . . . . 38
           6.11.7.  Framed-IPv6-Route AVP . . . . . . . . . . . . . 38
           6.11.8.  Framed-IPv6-Pool AVP. . . . . . . . . . . . . . 38
     6.12. IPX Access . . . . . . . . . . . . . . . . . . . . . . . 38
           6.12.1.  Framed-IPX-Network AVP. . . . . . . . . . . . . 39
     6.13. AppleTalk Network Access . . . . . . . . . . . . . . . . 39
           6.13.1.  Framed-AppleTalk-Link AVP . . . . . . . . . . . 39
           6.13.2.  Framed-AppleTalk-Network AVP . . . . . . . . .  39
           6.13.3.  Framed-AppleTalk-Zone AVP . . . . . . . . . . . 40
     6.14. AppleTalk Remote Access. . . . . . . . . . . . . . . . . 40
           6.14.1.  ARAP-Features AVP . . . . . . . . . . . . . . . 40
           6.14.2.  ARAP-Zone-Access AVP. . . . . . . . . . . . . . 40
     6.15. Non-Framed Access Authorization AVPs . . . . . . . . . . 40
           6.15.1.  Login-IP-Host AVP . . . . . . . . . . . . . . . 40
           6.15.2.  Login-IPv6-Host AVP . . . . . . . . . . . . . . 41
           6.15.3.  Login-Service AVP . . . . . . . . . . . . . . . 41
     6.16. TCP Services . . . . . . . . . . . . . . . . . . . . . . 42
           6.16.1.  Login-TCP-Port AVP . . . . . . . . . . . . . .  42
     6.17. LAT Services . . . . . . . . . . . . . . . . . . . . . . 42
           6.17.1.  Login-LAT-Service AVP . . . . . . . . . . . . . 42
           6.17.2.  Login-LAT-Node AVP. . . . . . . . . . . . . . . 43
           6.17.3.  Login-LAT-Group AVP . . . . . . . . . . . . . . 43
           6.17.4.  Login-LAT-Port AVP. . . . . . . . . . . . . . . 43
 7.  NAS Tunneling  . . . . . . . . . . . . . . . . . . . . . . . . 44
     7.1.  Tunneling AVP  . . . . . . . . . . . . . . . . . . . . . 44
     7.2.  Tunnel-Type AVP  . . . . . . . . . . . . . . . . . . . . 45
     7.3.  Tunnel-Medium-Type AVP . . . . . . . . . . . . . . . . . 46
     7.4.  Tunnel-Client-Endpoint AVP . . . . . . . . . . . . . . . 46
     7.5.  Tunnel-Server-Endpoint AVP . . . . . . . . . . . . . . . 47
     7.6.  Tunnel-Password AVP  . . . . . . . . . . . . . . . . . . 48
     7.7.  Tunnel-Private-Group-Id AVP  . . . . . . . . . . . . . . 48

Calhoun, et al. Standards Track [Page 3] RFC 4005 Diameter Network Access Server Application August 2005

     7.8.  Tunnel-Assignment-Id AVP . . . . . . . . . . . . . . . . 48
     7.9.  Tunnel-Preference AVP  . . . . . . . . . . . . . . . . . 49
     7.10. Tunnel-Client-Auth-Id AVP. . . . . . . . . . . . . . . . 50
     7.11. Tunnel-Server-Auth-Id AVP. . . . . . . . . . . . . . . . 50
 8.  NAS Accounting . . . . . . . . . . . . . . . . . . . . . . . . 50
     8.1.  Accounting-Input-Octets AVP  . . . . . . . . . . . . . . 51
     8.2.  Accounting-Output-Octets AVP . . . . . . . . . . . . . . 52
     8.3.  Accounting-Input-Packets AVP . . . . . . . . . . . . . . 52
     8.4.  Accounting-Output-Packets AVP  . . . . . . . . . . . . . 52
     8.5.  Acct-Session-Time AVP  . . . . . . . . . . . . . . . . . 52
     8.6.  Acct-Authentic AVP . . . . . . . . . . . . . . . . . . . 52
     8.7.  Accounting-Auth-Method AVP . . . . . . . . . . . . . . . 53
     8.8.  Acct-Delay-Time  . . . . . . . . . . . . . . . . . . . . 53
     8.9.  Acct-Link-Count  . . . . . . . . . . . . . . . . . . . . 54
     8.10. Acct-Tunnel-Connection AVP . . . . . . . . . . . . . . . 54
     8.11. Acct-Tunnel-Packets-Lost AVP . . . . . . . . . . . . . . 55
 9.  RADIUS/Diameter Protocol Interactions  . . . . . . . . . . . . 55
     9.1.  RADIUS Request Forwarded as Diameter Request . . . . . . 55
           9.1.1.   RADIUS Dynamic Authorization Considerations . . 59
     9.2.  Diameter Request Forwarded as RADIUS Request . . . . . . 60
           9.2.1.   RADIUS Dynamic Authorization Considerations . . 62
     9.3.  AVPs Used Only for Compatibility . . . . . . . . . . . . 63
           9.3.1.   NAS-Identifier AVP. . . . . . . . . . . . . . . 63
           9.3.2.   NAS-IP-Address AVP. . . . . . . . . . . . . . . 64
           9.3.3.   NAS-IPv6-Address AVP. . . . . . . . . . . . . . 65
           9.3.4.   State AVP . . . . . . . . . . . . . . . . . . . 65
           9.3.5.   Termination-Cause AVP Code Values . . . . . . . 66
           9.3.6.   Origin-AAA-Protocol . . . . . . . . . . . . . . 68
     9.4.  Prohibited RADIUS Attributes . . . . . . . . . . . . . . 69
     9.5.  Translatable Diameter AVPs . . . . . . . . . . . . . . . 69
     9.6.  RADIUS Vendor-Specific Attributes  . . . . . . . . . . . 69
           9.6.1.  Forwarding a Diameter Vendor Specific AVP as a
                   RADIUS VSA . . . . . . . . . . . . . . . . . . . 70
           9.6.2.  Forwarding a RADIUS VSA as a Diameter Vendor
                   Specific AVP . . . . . . . . . . . . . . . . . . 70
 10. AVP Occurrence Tables. . . . . . . . . . . . . . . . . . . . . 71
     10.1. AA-Request/Answer AVP Table. . . . . . . . . . . . . . . 71
     10.2. Accounting AVP Tables. . . . . . . . . . . . . . . . . . 73
           10.2.1.  Accounting Framed Access AVP Table. . . . . . . 74
           10.2.2.  Accounting Non-Framed Access AVP Table. . . . . 76
 11. IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 77
     11.1. Command Codes. . . . . . . . . . . . . . . . . . . . . . 77
     11.2. AVP Codes. . . . . . . . . . . . . . . . . . . . . . . . 78
     11.3. Application Identifier . . . . . . . . . . . . . . . . . 78
     11.4. CHAP-Algorithm AVP Values. . . . . . . . . . . . . . . . 78
     11.5. Accounting-Auth-Method AVP Values. . . . . . . . . . . . 78
     11.6. Origin-AAA-Protocol AVP Values . . . . . . . . . . . . . 78
 12. Security Considerations. . . . . . . . . . . . . . . . . . . . 78

Calhoun, et al. Standards Track [Page 4] RFC 4005 Diameter Network Access Server Application August 2005

 13. References . . . . . . . . . . . . . . . . . . . . . . . . . . 79
     13.1. Normative References . . . . . . . . . . . . . . . . . . 79
     13.2. Informative References . . . . . . . . . . . . . . . . . 80
 14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 83
 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 84
 Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 85

1. Introduction

 This document describes the Diameter protocol application used for
 AAA in the Network Access Server (NAS) environment.  When combined
 with the Diameter Base protocol [BASE], Transport Profile
 [DiamTrans], and EAP [DiamEAP] specifications, this Diameter NAS
 application specification satisfies NAS-related requirements defined
 in RFC 2989 [AAACriteria] and RFC 3169 [NASCriteria].
 Initial deployments of the Diameter protocol are expected to include
 legacy systems.  Therefore, this application has been carefully
 designed to ease the burden of protocol conversion between RADIUS and
 Diameter.  This is achieved by including the RADIUS attribute space
 to eliminate the need to perform many attribute translations.
 The interactions specified in this document between Diameter
 applications and RADIUS are to be applied to all Diameter
 applications.  In this sense, this document extends the Base Diameter
 protocol [BASE].
 First, this document describes the operation of a Diameter NAS
 application.  Then it defines the Diameter message Command-Codes.
 The following sections list the AVPs used in these messages, grouped
 by common usage.  These are session identification, authentication,
 authorization, tunneling, and accounting.  The authorization AVPs are
 further broken down by service type.  Interaction and backward
 compatibility issues with RADIUS are discussed in later sections.

1.1. Terminology

 The base Diameter [BASE] specification section 1.4 defines most of
 the terminology used in this document.  Additionally, the following
 terms and acronyms are used in this application:
 NAS (Network Access Server) - A device that provides an access
 service for a user to a network.  The service may be a network
 connection or a value-added service such as terminal emulation
 [NASModel].

Calhoun, et al. Standards Track [Page 5] RFC 4005 Diameter Network Access Server Application August 2005

 PPP (Point-to-Point Protocol) - A multiprotocol serial datalink.  PPP
 is the primary IP datalink used for dial-in NAS connection service
 [PPP].
 CHAP (Challenge Handshake Authentication Protocol) - An
 authentication process used in PPP [PPPCHAP].
 PAP (Password Authentication Protocol) - A deprecated PPP
 authentication process, but often used for backward compatibility
 [PAP].
 SLIP (Serial Line Interface Protocol) - A serial datalink that only
 supports IP.  A design prior to PPP.
 ARAP (Appletalk Remote Access Protocol) - A serial datalink for
 accessing Appletalk networks [ARAP].
 IPX (Internet Packet Exchange) - The network protocol used by NetWare
 networks [IPX].
 LAT (Local Area Transport) - A Digital Equipment Corp. LAN protocol
 for terminal services [LAT].
 VPN (Virtual Private Network) - In this document, this term is used
 to describe access services that use tunneling methods.

1.2. Requirements Language

 In this document, the key words "MAY", "MUST", "MUST NOT",
 "OPTIONAL", "RECOMMENDED", "SHOULD", and "SHOULD NOT" are to be
 interpreted as described in [Keywords].

1.3. Advertising Application Support

 Diameter applications conforming to this specification MUST advertise
 support by including the value of one (1) in the Auth-Application-Id
 of Capabilities-Exchange-Request (CER), AA-Request (AAR), and AA-
 Answer (AAA) messages.  All other messages are defined by [BASE] and
 use the Base application id value.

2. NAS Calls, Ports, and Sessions

 The arrival of a new call or service connection at a port of a
 Network Access Server (NAS) starts a Diameter NAS message exchange.
 Information about the call, the identity of the user, and the user's
 authentication information are packaged into a Diameter AA-Request
 (AAR) message and sent to a server.

Calhoun, et al. Standards Track [Page 6] RFC 4005 Diameter Network Access Server Application August 2005

 The server processes the information and responds with a Diameter
 AA-Answer (AAA) message that contains authorization information for
 the NAS, or a failure code (Result-Code AVP).  A value of
 DIAMETER_MULTI_ROUND_AUTH indicates an additional authentication
 exchange, and several AAR and AAA messages may be exchanged until the
 transaction completes.
 Depending on the Auth-Request-Type AVP, the Diameter protocol allows
 authorization-only requests that contain no authentication
 information from the client.  This capability goes beyond the Call
 Check capabilities described in section 5.6 of [RADIUS] in that no
 access decision is requested.  As a result, service cannot be started
 as a result of a response to an authorization-only request without
 introducing a significant security vulnerability.
 Since no equivalent capability exists in RADIUS, authorization-only
 requests from a NAS implementing Diameter may not be easily
 translated to an equivalent RADIUS message by a Diameter/RADIUS
 gateway.  For example, when a Diameter authorization-only request
 cannot be translated to a RADIUS Call Check, it would be necessary
 for the Diameter/RADIUS gateway to add authentication information to
 the RADIUS Access Request.  On receiving the Access-Reply, the
 Diameter/RADIUS gateway would need to discard the access decision
 (Accept/Reject).  It is not clear whether these translations can be
 accomplished without adding significant security vulnerabilities.

2.1. Diameter Session Establishment

 When the authentication or authorization exchange completes
 successfully, the NAS application SHOULD start a session context.  If
 the Result-Code of DIAMETER_MULTI_ROUND_AUTH is returned, the
 exchange continues until a success or error is returned.
 If accounting is active, the application MUST also send an Accounting
 message [BASE].  An Accounting-Record-Type of START_RECORD is sent
 for a new session.  If a session fails to start, the EVENT_RECORD
 message is sent with the reason for the failure described.
 Note that the return of an unsupportable Accounting-Realtime-Required
 value [BASE] would result in a failure to establish the session.

2.2. Diameter Session Reauthentication or Reauthorization

 The Diameter Base protocol allows users to be periodically
 reauthenticated and/or reauthorized.  In such instances, the
 Session-Id AVP in the AAR message MUST be the same as the one present
 in the original authentication/authorization message.

Calhoun, et al. Standards Track [Page 7] RFC 4005 Diameter Network Access Server Application August 2005

 A Diameter server informs the NAS of the maximum time allowed before
 reauthentication or reauthorization via the Authorization-Lifetime
 AVP [BASE].  A NAS MAY reauthenticate and/or reauthorize before the
 end, but A NAS MUST reauthenticate and/or reauthorize at the end of
 the period provided by the Authorization-Lifetime AVP.  The failure
 of a reauthentication exchange will terminate the service.
 Furthermore, it is possible for Diameter servers to issue an
 unsolicited reauthentication and/or reauthorization request (e.g.,
 Re-Auth-Request (RAR) message [BASE]) to the NAS.  Upon receipt of
 such a message, the NAS MUST respond to the request with a Re-Auth-
 Answer (RAA) message [BASE].
 If the RAR properly identifies an active session, the NAS will
 initiate a new local reauthentication or authorization sequence as
 indicated by the Re-Auth-Request-Type value.  This will cause the NAS
 to send a new AAR message using the existing Session-Id.  The server
 will respond with an AAA message to specify the new service
 parameters.
 If accounting is active, every change of authentication or
 authorization SHOULD generate an accounting message.  If the NAS
 service is a continuation of the prior user context, then an
 Accounting-Record-Type of INTERIM_RECORD indicating the new session
 attributes and cumulative status would be appropriate.  If a new user
 or a significant change in authorization is detected by the NAS, then
 the service may send two messages of the types STOP_RECORD and
 START_RECORD.  Accounting may change the subsession identifiers
 (Acct-Session-ID, or Acct-Sub-Session-Id) to indicate such sub-
 sessions.  A service may also use a different Session-Id value for
 accounting (see [BASE] section 9.6).
 However, the Diameter Session-ID AVP value used for the initial
 authorization exchange MUST be used to generate an STR message when
 the session context is terminated.

2.3. Diameter Session Termination

 When a NAS receives an indication that a user's session is being
 disconnected by the client (e.g., LCP Terminate is received) or an
 administrative command, the NAS MUST issue a Session-Termination-
 Request (STR) [BASE] to its Diameter Server.  This will ensure that
 any resources maintained on the servers are freed appropriately.
 Furthermore, a NAS that receives an Abort-Session-Request (ASR)
 [BASE] MUST issue an ASA if the session identified is active and
 disconnect the PPP (or tunneling) session.

Calhoun, et al. Standards Track [Page 8] RFC 4005 Diameter Network Access Server Application August 2005

 If accounting is active, an Accounting STOP_RECORD message [BASE]
 MUST be sent upon termination of the session context.
 More information on Diameter Session Termination is included in
 [BASE] sections 8.4 and 8.5.

3. NAS Messages

 This section defines the Diameter message Command-Code [BASE] values
 that MUST be supported by all Diameter implementations conforming to
 this specification.  The Command Codes are as follows:
    Command-Name                  Abbrev.  Code   Reference
    -------------------------------------------------------
    AA-Request                      AAR     265     3.1
    AA-Answer                       AAA     265     3.2
    Re-Auth-Request                 RAR     258     3.3
    Re-Auth-Answer                  RAA     258     3.4
    Session-Termination-Request     STR     275     3.5
    Session-Termination-Answer      STA     275     3.6
    Abort-Session-Request           ASR     274     3.7
    Abort-Session-Answer            ASA     274     3.8
    Accounting-Request              ACR     271     3.9
    Accounting-Answer               ACA     271     3.10

3.1. AA-Request (AAR) Command

 The AA-Request (AAR), which is indicated by setting the Command-Code
 field to 265 and the 'R' bit in the Command Flags field, is used to
 request authentication and/or authorization for a given NAS user.
 The type of request is identified through the Auth-Request-Type AVP
 [BASE].  The recommended value for most RADIUS interoperabily
 situations is AUTHORIZE_AUTHENTICATE.
 If Authentication is requested, the User-Name attribute SHOULD be
 present, as well as any additional authentication AVPs that would
 carry the password information.  A request for authorization SHOULD
 only include the information from which the authorization will be
 performed, such as the User-Name, Called-Station-Id, or Calling-
 Station-Id AVPs.  All requests SHOULD contain AVPs uniquely
 identifying the source of the call, such as Origin-Host and NAS-Port.
 Certain networks MAY use different AVPs for authorization purposes.
 A request for authorization will include some AVPs defined in section
 6.
 It is possible for a single session to be authorized first and then
 for an authentication request to follow.

Calhoun, et al. Standards Track [Page 9] RFC 4005 Diameter Network Access Server Application August 2005

 This AA-Request message MAY be the result of a multi-round
 authentication exchange, which occurs when the AA-Answer message is
 received with the Result-Code AVP set to DIAMETER_MULTI_ROUND_AUTH.
 A subsequent AAR message SHOULD be sent, with the User-Password AVP
 that includes the user's response to the prompt, and MUST include any
 State AVPs that were present in the AAA message.
 Message Format
    <AA-Request> ::= < Diameter Header: 265, REQ, PXY >
                     < Session-Id >
                     { Auth-Application-Id }
                     { Origin-Host }
                     { Origin-Realm }
                     { Destination-Realm }
                     { Auth-Request-Type }
                     [ Destination-Host ]
                     [ NAS-Identifier ]
                     [ NAS-IP-Address ]
                     [ NAS-IPv6-Address ]
                     [ NAS-Port ]
                     [ NAS-Port-Id ]
                     [ NAS-Port-Type ]
                     [ Origin-AAA-Protocol ]
                     [ Origin-State-Id ]
                     [ Port-Limit ]
                     [ User-Name ]
                     [ User-Password ]
                     [ Service-Type ]
                     [ State ]
                     [ Authorization-Lifetime ]
                     [ Auth-Grace-Period ]
                     [ Auth-Session-State ]
                     [ Callback-Number ]
                     [ Called-Station-Id ]
                     [ Calling-Station-Id ]
                     [ Originating-Line-Info ]
                     [ Connect-Info ]
                     [ CHAP-Auth ]
                     [ CHAP-Challenge ]
                   * [ Framed-Compression ]
                     [ Framed-Interface-Id ]
                     [ Framed-IP-Address ]
                   * [ Framed-IPv6-Prefix ]
                     [ Framed-IP-Netmask ]
                     [ Framed-MTU ]
                     [ Framed-Protocol ]
                     [ ARAP-Password ]
                     [ ARAP-Security ]

Calhoun, et al. Standards Track [Page 10] RFC 4005 Diameter Network Access Server Application August 2005

  • [ ARAP-Security-Data ]
  • [ Login-IP-Host ]
  • [ Login-IPv6-Host ]

[ Login-LAT-Group ]

                     [ Login-LAT-Node ]
                     [ Login-LAT-Port ]
                     [ Login-LAT-Service ]
                   * [ Tunneling ]
                   * [ Proxy-Info ]
                   * [ Route-Record ]
                   * [ AVP ]

3.2. AA-Answer (AAA) Command

 The AA-Answer (AAA) message is indicated by setting the Command-Code
 field to 265 and clearing the 'R' bit in the Command Flags field.  It
 is sent in response to the AA-Request (AAR) message.  If
 authorization was requested, a successful response will include the
 authorization AVPs appropriate for the service being provided, as
 defined in section 6.
 For authentication exchanges requiring more than a single round trip,
 the server MUST set the Result-Code AVP to DIAMETER_MULTI_ROUND_AUTH.
 An AAA message with this result code MAY include one Reply-Message or
 more and MAY include zero or one State AVPs.
 If the Reply-Message AVP was present, the network access server
 SHOULD send the text to the user's client to display to the user,
 instructing the client to prompt the user for a response.  For
 example, this capability can be achieved in PPP via PAP.  If the
 access client is unable to prompt the user for a new response, it
 MUST treat the AA-Answer (AAA) with the Reply-Message AVP as an error
 and deny access.
 Message Format
    <AA-Answer> ::= < Diameter Header: 265, PXY >
                    < Session-Id >
                    { Auth-Application-Id }
                    { Auth-Request-Type }
                    { Result-Code }
                    { Origin-Host }
                    { Origin-Realm }
                    [ User-Name ]
                    [ Service-Type ]
                  * [ Class ]
                  * [ Configuration-Token ]
                    [ Acct-Interim-Interval ]

Calhoun, et al. Standards Track [Page 11] RFC 4005 Diameter Network Access Server Application August 2005

                    [ Error-Message ]
                    [ Error-Reporting-Host ]
                  * [ Failed-AVP ]
                    [ Idle-Timeout ]
                    [ Authorization-Lifetime ]
                    [ Auth-Grace-Period ]
                    [ Auth-Session-State ]
                    [ Re-Auth-Request-Type ]
                    [ Multi-Round-Time-Out ]
                    [ Session-Timeout ]
                    [ State ]
                  * [ Reply-Message ]
                    [ Origin-AAA-Protocol ]
                    [ Origin-State-Id ]
                  * [ Filter-Id ]
                    [ Password-Retry ]
                    [ Port-Limit ]
                    [ Prompt ]
                    [ ARAP-Challenge-Response ]
                    [ ARAP-Features ]
                    [ ARAP-Security ]
                  * [ ARAP-Security-Data ]
                    [ ARAP-Zone-Access ]
                    [ Callback-Id ]
                    [ Callback-Number ]
                    [ Framed-Appletalk-Link ]
                  * [ Framed-Appletalk-Network ]
                    [ Framed-Appletalk-Zone ]
                  * [ Framed-Compression ]
                    [ Framed-Interface-Id ]
                    [ Framed-IP-Address ]
                  * [ Framed-IPv6-Prefix ]
                    [ Framed-IPv6-Pool ]
                  * [ Framed-IPv6-Route ]
                    [ Framed-IP-Netmask ]
                  * [ Framed-Route ]
                    [ Framed-Pool ]
                    [ Framed-IPX-Network ]
                    [ Framed-MTU ]
                    [ Framed-Protocol ]
                    [ Framed-Routing ]
                  * [ Login-IP-Host ]
                  * [ Login-IPv6-Host ]
                    [ Login-LAT-Group ]
                    [ Login-LAT-Node ]
                    [ Login-LAT-Port ]
                    [ Login-LAT-Service ]
                    [ Login-Service ]

Calhoun, et al. Standards Track [Page 12] RFC 4005 Diameter Network Access Server Application August 2005

                    [ Login-TCP-Port ]
                  * [ NAS-Filter-Rule ]
                  * [ QoS-Filter-Rule ]
                  * [ Tunneling ]
                  * [ Redirect-Host ]
                    [ Redirect-Host-Usage ]
                    [ Redirect-Max-Cache-Time ]
                  * [ Proxy-Info ]
                  * [ AVP ]

3.3. Re-Auth-Request (RAR) Command

 A Diameter server may initiate a re-authentication and/or re-
 authorization service for a particular session by issuing a Re-Auth-
 Request (RAR) message [BASE].
 For example, for pre-paid services, the Diameter server that
 originally authorized a session may need some confirmation that the
 user is still using the services.
 If a NAS receives an RAR message with Session-Id equal to a currently
 active session and a Re-Auth-Type that includes authentication, it
 MUST initiate a re-authentication toward the user, if the service
 supports this particular feature.
 Message Format
    <RA-Request>  ::= < Diameter Header: 258, REQ, PXY >
                     < Session-Id >
                     { Origin-Host }
                     { Origin-Realm }
                     { Destination-Realm }
                     { Destination-Host }
                     { Auth-Application-Id }
                     { Re-Auth-Request-Type }
                     [ User-Name ]
                     [ Origin-AAA-Protocol ]
                     [ Origin-State-Id ]
                     [ NAS-Identifier ]
                     [ NAS-IP-Address ]
                     [ NAS-IPv6-Address ]
                     [ NAS-Port ]
                     [ NAS-Port-Id ]
                     [ NAS-Port-Type ]
                     [ Service-Type ]
                     [ Framed-IP-Address ]
                     [ Framed-IPv6-Prefix ]
                     [ Framed-Interface-Id ]

Calhoun, et al. Standards Track [Page 13] RFC 4005 Diameter Network Access Server Application August 2005

                     [ Called-Station-Id ]
                     [ Calling-Station-Id ]
                     [ Originating-Line-Info ]
                     [ Acct-Session-Id ]
                     [ Acct-Multi-Session-Id ]
                     [ State ]
                   * [ Class ]
                     [ Reply-Message ]
                   * [ Proxy-Info ]
                   * [ Route-Record ]
                   * [ AVP ]

3.4. Re-Auth-Answer (RAA) Command

 The Re-Auth-Answer (RAA) message [BASE] is sent in response to the
 RAR.  The Result-Code AVP MUST be present and indicates the
 disposition of the request.
 A successful RAA transaction MUST be followed by an AAR message.
 Message Format
    <RA-Answer>  ::= < Diameter Header: 258, PXY >
                     < Session-Id >
                     { Result-Code }
                     { Origin-Host }
                     { Origin-Realm }
                     [ User-Name ]
                     [ Origin-AAA-Protocol ]
                     [ Origin-State-Id ]
                     [ Error-Message ]
                     [ Error-Reporting-Host ]
                   * [ Failed-AVP ]
                   * [ Redirected-Host ]
                     [ Redirected-Host-Usage ]
                     [ Redirected-Host-Cache-Time ]
                     [ Service-Type ]
                   * [ Configuration-Token ]
                     [ Idle-Timeout ]
                     [ Authorization-Lifetime ]
                     [ Auth-Grace-Period ]
                     [ Re-Auth-Request-Type ]
                     [ State ]
                   * [ Class ]
                   * [ Reply-Message ]
                     [ Prompt ]
                   * [ Proxy-Info ]
                   * [ AVP ]

Calhoun, et al. Standards Track [Page 14] RFC 4005 Diameter Network Access Server Application August 2005

3.5. Session-Termination-Request (STR) Command

 The Session-Termination-Request (STR) message [BASE] is sent by the
 NAS to inform the Diameter Server that an authenticated and/or
 authorized session is being terminated.
 Message Format
    <ST-Request> ::= < Diameter Header: 275, REQ, PXY >
                    < Session-Id >
                    { Origin-Host }
                    { Origin-Realm }
                    { Destination-Realm }
                    { Auth-Application-Id }
                    { Termination-Cause }
                    [ User-Name ]
                    [ Destination-Host ]
                  * [ Class ]
                    [ Origin-AAA-Protocol ]
                    [ Origin-State-Id ]
                  * [ Proxy-Info ]
                  * [ Route-Record ]
                  * [ AVP ]

3.6. Session-Termination-Answer (STA) Command

 The Session-Termination-Answer (STA) message [BASE] is sent by the
 Diameter Server to acknowledge the notification that the session has
 been terminated.  The Result-Code AVP MUST be present and MAY contain
 an indication that an error occurred while the STR was being
 serviced.
 Upon sending or receiving the STA, the Diameter Server MUST release
 all resources for the session indicated by the Session-Id AVP.  Any
 intermediate server in the Proxy-Chain MAY also release any
 resources, if necessary.
 Message Format
    <ST-Answer>  ::= < Diameter Header: 275, PXY >
                     < Session-Id >
                     { Result-Code }
                     { Origin-Host }
                     { Origin-Realm }
                     [ User-Name ]
                   * [ Class ]
                     [ Error-Message ]
                     [ Error-Reporting-Host ]

Calhoun, et al. Standards Track [Page 15] RFC 4005 Diameter Network Access Server Application August 2005

  • [ Failed-AVP ]

[ Origin-AAA-Protocol ]

                     [ Origin-State-Id ]
                   * [ Redirect-Host ]
                     [ Redirect-Host-Usase ]
                     [ Redirect-Max-Cache-Time ]
                   * [ Proxy-Info ]
                   * [ AVP ]

3.7. Abort-Session-Request (ASR) Command

 The Abort-Session-Request (ASR) message [BASE] may be sent by any
 server to the NAS providing session service, to request that the
 session identified by the Session-Id be stopped.
 Message Format
    <AS-Request>  ::= < Diameter Header: 274, REQ, PXY >
                     < Session-Id >
                     { Origin-Host }
                     { Origin-Realm }
                     { Destination-Realm }
                     { Destination-Host }
                     { Auth-Application-Id }
                     [ User-Name ]
                     [ Origin-AAA-Protocol ]
                     [ Origin-State-Id ]
                     [ NAS-Identifier ]
                     [ NAS-IP-Address ]
                     [ NAS-IPv6-Address ]
                     [ NAS-Port ]
                     [ NAS-Port-Id ]
                     [ NAS-Port-Type ]
                     [ Service-Type ]
                     [ Framed-IP-Address ]
                     [ Framed-IPv6-Prefix ]
                     [ Framed-Interface-Id ]
                     [ Called-Station-Id ]
                     [ Calling-Station-Id ]
                     [ Originating-Line-Info ]
                     [ Acct-Session-Id ]
                     [ Acct-Multi-Session-Id ]
                     [ State ]
                   * [ Class ]
                   * [ Reply-Message ]
                   * [ Proxy-Info ]
                   * [ Route-Record ]
                   * [ AVP ]

Calhoun, et al. Standards Track [Page 16] RFC 4005 Diameter Network Access Server Application August 2005

3.8. Abort-Session-Answer (ASA) Command

 The ASA message [BASE] is sent in response to the ASR.  The Result-
 Code AVP MUST be present and indicates the disposition of the
 request.
 If the session identified by Session-Id in the ASR was successfully
 terminated, Result-Code is set to DIAMETER_SUCCESS.  If the session
 is not currently active, Result-Code is set to
 DIAMETER_UNKNOWN_SESSION_ID.  If the access device does not stop the
 session for any other reason, Result-Code is set to
 DIAMETER_UNABLE_TO_COMPLY.
 Message Format
    <AS-Answer>  ::= < Diameter Header: 274, PXY >
                     < Session-Id >
                     { Result-Code }
                     { Origin-Host }
                     { Origin-Realm }
                     [ User-Name ]
                     [ Origin-AAA-Protocol ]
                     [ Origin-State-Id ]
                     [ State]
                     [ Error-Message ]
                     [ Error-Reporting-Host ]
                   * [ Failed-AVP ]
                   * [ Redirected-Host ]
                     [ Redirected-Host-Usage ]
                     [ Redirected-Max-Cache-Time ]
                   * [ Proxy-Info ]
                   * [ AVP ]

3.9. Accounting-Request (ACR) Command

 The ACR message [BASE] is sent by the NAS to report its session
 information to a target server downstream.
 Either of Acct-Application-Id or Vendor-Specific-Application-Id AVPs
 MUST be present.  If the Vendor-Specific-Application-Id grouped AVP
 is present, it must have an Acct-Application-Id inside.
 The AVPs listed in the Base MUST be assumed to be present, as
 appropriate.  NAS service-specific accounting AVPs SHOULD be present
 as described in section 8 and the rest of this specification.

Calhoun, et al. Standards Track [Page 17] RFC 4005 Diameter Network Access Server Application August 2005

 Message Format
    <AC-Request> ::= < Diameter Header: 271, REQ, PXY >
                    < Session-Id >
                    { Origin-Host }
                    { Origin-Realm }
                    { Destination-Realm }
                    { Accounting-Record-Type }
                    { Accounting-Record-Number }
                    [ Acct-Application-Id ]
                    [ Vendor-Specific-Application-Id ]
                    [ User-Name ]
                    [ Accounting-Sub-Session-Id ]
                    [ Acct-Session-Id ]
                    [ Acct-Multi-Session-Id ]
                    [ Origin-AAA-Protocol ]
                    [ Origin-State-Id ]
                    [ Destination-Host ]
                    [ Event-Timestamp ]
                    [ Acct-Delay-Time ]
                    [ NAS-Identifier ]
                    [ NAS-IP-Address ]
                    [ NAS-IPv6-Address ]
                    [ NAS-Port ]
                    [ NAS-Port-Id ]
                    [ NAS-Port-Type ]
                  * [ Class ]
                    [ Service-Type ]
                    [ Termination-Cause ]
                    [ Accounting-Input-Octets ]
                    [ Accounting-Input-Packets ]
                    [ Accounting-Output-Octets ]
                    [ Accounting-Output-Packets ]
                    [ Acct-Authentic ]
                    [ Accounting-Auth-Method ]
                    [ Acct-Link-Count ]
                    [ Acct-Session-Time ]
                    [ Acct-Tunnel-Connection ]
                    [ Acct-Tunnel-Packets-Lost ]
                    [ Callback-Id ]
                    [ Callback-Number ]
                    [ Called-Station-Id ]
                    [ Calling-Station-Id ]
                  * [ Connection-Info ]
                    [ Originating-Line-Info ]
                    [ Authorization-Lifetime ]
                    [ Session-Timeout ]
                    [ Idle-Timeout ]

Calhoun, et al. Standards Track [Page 18] RFC 4005 Diameter Network Access Server Application August 2005

                    [ Port-Limit ]
                    [ Accounting-Realtime-Required ]
                    [ Acct-Interim-Interval ]
                  * [ Filter-Id ]
                  * [ NAS-Filter-Rule ]
                  * [ Qos-Filter-Rule ]
                    [ Framed-AppleTalk-Link ]
                    [ Framed-AppleTalk-Network ]
                    [ Framed-AppleTalk-Zone ]
                    [ Framed-Compression ]
                    [ Framed-Interface-Id ]
                    [ Framed-IP-Address ]
                    [ Framed-IP-Netmask ]
                  * [ Framed-IPv6-Prefix ]
                    [ Framed-IPv6-Pool ]
                  * [ Framed-IPv6-Route ]
                    [ Framed-IPX-Network ]
                    [ Framed-MTU ]
                    [ Framed-Pool ]
                    [ Framed-Protocol ]
                  * [ Framed-Route ]
                    [ Framed-Routing ]
                  * [ Login-IP-Host ]
                  * [ Login-IPv6-Host ]
                    [ Login-LAT-Group ]
                    [ Login-LAT-Node ]
                    [ Login-LAT-Port ]
                    [ Login-LAT-Service ]
                    [ Login-Service ]
                    [ Login-TCP-Port ]
                  * [ Tunneling ]
                  * [ Proxy-Info ]
                  * [ Route-Record ]
                  * [ AVP ]

3.10. Accounting-Answer (ACA) Command

 The ACA message [BASE] is used to acknowledge an Accounting-Request
 command.  The Accounting-Answer command contains the same Session-Id
 as the Request.  If the Accounting-Request was protected by end-to-
 end security, then the corresponding ACA message MUST be protected as
 well.
 Only the target Diameter Server or home Diameter Server SHOULD
 respond with the Accounting-Answer command.
 Either Acct-Application-Id or Vendor-Specific-Application-Id AVPs
 MUST be present, as it was in the request.

Calhoun, et al. Standards Track [Page 19] RFC 4005 Diameter Network Access Server Application August 2005

 The AVPs listed in the Base MUST be assumed to be present, as
 appropriate.  NAS service-specific accounting AVPs SHOULD be present
 as described in section 8 and the rest of this specification.
 Message Format
    <AC-Answer> ::= < Diameter Header: 271, PXY >
                    < Session-Id >
                    { Result-Code }
                    { Origin-Host }
                    { Origin-Realm }
                    { Accounting-Record-Type }
                    { Accounting-Record-Number }
                    [ Acct-Application-Id ]
                    [ Vendor-Specific-Application-Id ]
                    [ User-Name ]
                    [ Accounting-Sub-Session-Id ]
                    [ Acct-Session-Id ]
                    [ Acct-Multi-Session-Id ]
                    [ Event-Timestamp ]
                    [ Error-Message ]
                    [ Error-Reporting-Host ]
                  * [ Failed-AVP ]
                    [ Origin-AAA-Protocol ]
                    [ Origin-State-Id ]
                    [ NAS-Identifier ]
                    [ NAS-IP-Address ]
                    [ NAS-IPv6-Address ]
                    [ NAS-Port ]
                    [ NAS-Port-Id ]
                    [ NAS-Port-Type ]
                    [ Service-Type ]
                    [ Termination-Cause ]
                    [ Accounting-Realtime-Required ]
                    [ Acct-Interim-Interval ]
                  * [ Class ]
                  * [ Proxy-Info ]
                  * [ Route-Record ]
                  * [ AVP ]

4. NAS Session AVPs

 Diameter reserves the AVP Codes 0 - 255 for RADIUS functions that are
 implemented in Diameter.
 AVPs new to Diameter have code values of 256 and greater.  A Diameter
 message that includes one of these AVPs may represent functions not
 present in the RADIUS environment and may cause interoperability

Calhoun, et al. Standards Track [Page 20] RFC 4005 Diameter Network Access Server Application August 2005

 issues, should the request traverse an AAA system that only supports
 the RADIUS protocol.
 Some RADIUS attributes are not allowed or supported directly in
 Diameter.  See section 9 for more information.

4.1. Call and Session Information

 This section contains the AVPs specific to NAS Diameter applications
 that are needed to identify the call and session context and status
 information.  On a request, this information allows the server to
 qualify the session.
 These AVPs are used in addition to the Base AVPs of:
    Session-Id
    Auth-Application-Id
    Origin-Host
    Origin-Realm
    Auth-Request-Type
    Termination-Cause
 The following table describes the session level AVPs; their AVP Code
 values, types, and possible flag values; and whether the AVP MAY be
 encrypted.
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT|  NOT|Encr|
 -----------------------------------------|----+-----+----+-----|----|
 NAS-Port           5   4.2    Unsigned32 | M  |  P  |    |  V  | Y  |
 NAS-Port-Id       87   4.3    UTF8String | M  |  P  |    |  V  | Y  |
 NAS-Port-Type     61   4.4    Enumerated | M  |  P  |    |  V  | Y  |
 Called-Station-Id 30   4.5    UTF8String | M  |  P  |    |  V  | Y  |
 Calling-Station-  31   4.6    UTF8String | M  |  P  |    |  V  | Y  |
   Id                                     |    |     |    |     |    |
 Connect-Info      77   4.7    UTF8String | M  |  P  |    |  V  | Y  |
 Originating-Line- 94   4.8    OctetString|    | M,P |    |  V  | Y  |
   Info                                   |    |     |    |     |    |
 Reply-Message     18   4.9    UTF8String | M  |  P  |    |  V  | Y  |
 -----------------------------------------|----+-----+----+-----|----|

Calhoun, et al. Standards Track [Page 21] RFC 4005 Diameter Network Access Server Application August 2005

4.2. NAS-Port AVP

 The NAS-Port AVP (AVP Code 5) is of type Unsigned32 and contains the
 physical or virtual port number of the NAS which is authenticating
 the user.  Note that "port" is meant in its sense as a service
 connection on the NAS, not as an IP protocol identifier.
 Either NAS-Port or NAS-Port-Id (AVP Code 87) SHOULD be present in
 AA-Request (AAR) commands if the NAS differentiates among its ports.

4.3. NAS-Port-Id AVP

 The NAS-Port-Id AVP (AVP Code 87) is of type UTF8String and consists
 of ASCII text identifying the port of the NAS authenticating the
 user.  Note that "port" is meant in its sense as a service connection
 on the NAS, not as an IP protocol identifier.
 Either NAS-Port or NAS-Port-Id SHOULD be present in AA-Request (AAR)
 commands if the NAS differentiates among its ports.  NAS-Port-Id is
 intended for use by NASes that cannot conveniently number their
 ports.

4.4. NAS-Port-Type AVP

 The NAS-Port-Type AVP (AVP Code 61) is of type Enumerated and
 contains the type of the port on which the NAS is authenticating the
 user.  This AVP SHOULD be present if the NAS uses the same NAS-Port
 number ranges for different service types concurrently.
 The supported values are defined in [RADIUSTypes].  The following
 list is informational and subject to change by the IANA.
     0   Async
     1   Sync
     2   ISDN Sync
     3   ISDN Async V.120
     4   ISDN Async V.110
     5   Virtual
     6   PIAFS
     7   HDLC Clear Channel
     8   X.25
     9   X.75
    10   G.3 Fax
    11   SDSL - Symmetric DSL
    12   ADSL-CAP - Asymmetric DSL, Carrierless Amplitude Phase
            Modulation
    13   ADSL-DMT - Asymmetric DSL, Discrete Multi-Tone
    14   IDSL - ISDN Digital Subscriber Line

Calhoun, et al. Standards Track [Page 22] RFC 4005 Diameter Network Access Server Application August 2005

    15   Ethernet
    16   xDSL - Digital Subscriber Line of unknown type
    17   Cable
    18   Wireless - Other
    19   Wireless - IEEE 802.11
    20   Token-Ring   [RAD802.1X]
    21   FDDI         [RAD802.1X]
    22   Wireless - CDMA2000
    23   Wireless - UMTS
    24   Wireless - 1X-EV
    25   IAPP    [IEEE 802.11f]

4.5. Called-Station-Id AVP

 The Called-Station-Id AVP (AVP Code 30) is of type UTF8String and
 allows the NAS to send the ASCII string describing the layer 2
 address the user contacted in the request.  For dialup access, this
 can be a phone number obtained by using Dialed Number Identification
 (DNIS) or a similar technology.  Note that this may be different from
 the phone number the call comes in on.  For use with IEEE 802 access,
 the Called-Station-Id MAY contain a MAC address formatted as
 described in [RAD802.1X].  It SHOULD only be present in
 authentication and/or authorization requests.
 If the Auth-Request-Type AVP is set to authorization-only and the
 User-Name AVP is absent, the Diameter Server MAY perform
 authorization based on this field.  This can be used by a NAS to
 request whether a call should be answered based on the DNIS.
 The codification of this field's allowed usage range is outside the
 scope of this specification.

4.6. Calling-Station-Id AVP

 The Calling-Station-Id AVP (AVP Code 31) is of type UTF8String and
 allows the NAS to send the ASCII string describing the layer 2
 address from which the user connected in the request.  For dialup
 access, this is the phone number the call came from, using Automatic
 Number Identification (ANI) or a similar technology.  For use with
 IEEE 802 access, the Calling-Station-Id AVP MAY contain a MAC
 address, formated as described in [RAD802.1X].  It SHOULD only be
 present in authentication and/or authorization requests.
 If the Auth-Request-Type AVP is set to authorization-only and the
 User-Name AVP is absent, the Diameter Server MAY perform
 authorization based on this field.  This can be used by a NAS to
 request whether a call should be answered based on the layer 2
 address (ANI, MAC Address, etc.)

Calhoun, et al. Standards Track [Page 23] RFC 4005 Diameter Network Access Server Application August 2005

 The codification of this field's allowed usage range is outside the
 scope of this specification.

4.7. Connect-Info AVP

 The Connect-Info AVP (AVP Code 77) is of type UTF8String and is sent
 in the AA-Request message or ACR STOP message.  When sent in the
 Access-Request, it indicates the nature of the user's connection.
 The connection speed SHOULD be included at the beginning of the first
 Connect-Info AVP in the message.  If the transmit and receive
 connection speeds differ, both may be included in the first AVP with
 the transmit speed listed first (the speed the NAS modem transmits
 at), then a slash (/), then the receive speed, and then other
 optional information.
 For example: "28800 V42BIS/LAPM" or "52000/31200 V90"
 More than one Connect-Info attribute may be present in an
 Accounting-Request packet to accommodate expected efforts by the ITU
 to have modems report more connection information in a standard
 format that might exceed 252 octets.
 If sent in the ACR STOP, this attribute may summarize statistics
 relating to session quality.  For example, in IEEE 802.11, the
 Connect-Info attribute may contain information on the number of link
 layer retransmissions.  The exact format of this attribute is
 implementation specific.

4.8. Originating-Line-Info AVP

 The Originating-Line-Info AVP (AVP Code 94) is of type OctetString
 and is sent by the NAS system to convey information about the origin
 of the call from an SS7 system.
 The originating line information (OLI) element indicates the nature
 and/or characteristics of the line from which a call originated
 (e.g., pay phone, hotel, cellular).  Telephone companies are starting
 to offer OLI to their customers as an option over Primary Rate
 Interface (PRI).  Internet Service Providers (ISPs) can use OLI in
 addition to Called-Station-Id and Calling-Station-Id attributes to
 differentiate customer calls and to define different services.
 The Value field contains two octets (00 - 99).  ANSI T1.113 and
 BELLCORE 394 can be used for additional information about these
 values and their use.  For more information on current assignment
 values, see [ANITypes].

Calhoun, et al. Standards Track [Page 24] RFC 4005 Diameter Network Access Server Application August 2005

  Value   Description
 ------------------------------------------------------------
    00    Plain Old Telephone Service (POTS)
    01    Multiparty Line (more than 2)
    02    ANI Failure
    03    ANI Observed
    04    ONI Observed
    05    ANI Failure Observed
    06    Station Level Rating
    07    Special Operator Handling Required
    08    InterLATA Restricted
    10    Test Call
    20    Automatic Identified Outward Dialing (AIOD)
    23    Coin or Non-Coin
    24    Toll Free Service (Non-Pay Origination)
    25    Toll Free Service (Pay Origination)
    27    Toll Free Service (Coin Control Origination)
    29    Prison/Inmate Service
    30-32 Intercept
    30    Intercept (Blank)
    31    Intercept (Trouble)
    32    Intercept (Regular)
    34    Telco Operator Handled Call
    40-49 Unrestricted Use
    52    Outward Wide Area Telecommunications Service (OUTWATS)
    60    Telecommunications Relay Service (TRS)(Unrestricted)
    61    Cellular/Wireless PCS (Type 1)
    62    Cellular/Wireless PCS (Type 2)
    63    Cellular/Wireless PCS (Roaming)
    66    TRS (Hotel)
    67    TRS (Restricted)
    70    Pay Station, No Coin Control
    93    Access for Private Virtual Network Service

4.9. Reply-Message AVP

 The Reply-Message AVP (AVP Code 18) is of type UTF8String and
 contains text that MAY be displayed to the user.  When used in an
 AA-Answer message with a successful Result-Code AVP, it indicates
 success.  When found in an AAA message with a Result-Code other than
 DIAMETER_SUCCESS, the AVP contains a failure message.
 The Reply-Message AVP MAY indicate dialog text to prompt the user
 before another AA-Request attempt.  When used in an AA-Answer with a
 Result-Code of DIAMETER_MULTI_ROUND_AUTH or in an Re-Auth-Request
 message, it MAY contain a dialog text to prompt the user for a
 response.

Calhoun, et al. Standards Track [Page 25] RFC 4005 Diameter Network Access Server Application August 2005

 Multiple Reply-Messages MAY be included, and if any are displayed,
 they MUST be displayed in the same order as they appear in the
 Diameter message.

5. NAS Authentication AVPs

 This section defines the AVPs necessary to carry the authentication
 information in the Diameter protocol.  The functionality defined here
 provides a RADIUS-like AAA service over a more reliable and secure
 transport, as defined in the base protocol [BASE].
 The following table describes the AVPs; their AVP Code values, types,
 and possible flag values, and whether the AVP MAY be encrypted.
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT|  NOT|Encr|
 -----------------------------------------|----+-----+----+-----|----|
 User-Password      2   5.1    OctetString| M  |  P  |    |  V  | Y  |
 Password-Retry    75   5.2    Unsigned32 | M  |  P  |    |  V  | Y  |
 Prompt            76   5.3    Enumerated | M  |  P  |    |  V  | Y  |
 CHAP-Auth        402   5.4    Grouped    | M  |  P  |    |  V  | Y  |
 CHAP-Algorithm   403   5.5    Enumerated | M  |  P  |    |  V  | Y  |
 CHAP-Ident       404   5.6    OctetString| M  |  P  |    |  V  | Y  |
 CHAP-Response    405   5.7    OctetString| M  |  P  |    |  V  | Y  |
 CHAP-Challenge    60   5.8    OctetString| M  |  P  |    |  V  | Y  |
 ARAP-Password     70   5.9    OctetString| M  |  P  |    |  V  | Y  |
 ARAP-Challenge-   84   5.10   OctetString| M  |  P  |    |  V  | Y  |
   Response                               |    |     |    |     |    |
 ARAP-Security     73   5.11   Unsigned32 | M  |  P  |    |  V  | Y  |
 ARAP-Security-    74   5.12   OctetString| M  |  P  |    |  V  | Y  |
   Data                                   |    |     |    |     |    |
 -----------------------------------------|----+-----+----+-----|----|

5.1. User-Password AVP

 The User-Password AVP (AVP Code 2) is of type OctetString and
 contains the password of the user to be authenticated, or the user's
 input in a multi-round authentication exchange.
 The User-Password AVP contains a user password or one-time password
 and therefore represents sensitive information.  As required in
 [BASE], Diameter messages are encrypted by using IPsec or TLS.
 Unless this AVP is used for one-time passwords, the User-Password AVP

Calhoun, et al. Standards Track [Page 26] RFC 4005 Diameter Network Access Server Application August 2005

 SHOULD NOT be used in untrusted proxy environments without encrypting
 it by using end-to-end security techniques, such as the proposed CMS
 Security [DiamCMS].
 The clear-text password (prior to encryption) MUST NOT be longer than
 128 bytes in length.

5.2. Password-Retry AVP

 The Password-Retry AVP (AVP Code 75) is of type Unsigned32 and MAY be
 included in the AA-Answer if the Result-Code indicates an
 authentication failure.  The value of this AVP indicates how many
 authentication attempts a user is permitted before being
 disconnected.  This AVP is primarily intended for use when the
 Framed-Protocol AVP (see section 6.10.1) is set to ARAP.

5.3. Prompt AVP

 The Prompt AVP (AVP Code 76) is of type Enumerated and MAY be present
 in the AA-Answer message.  When present, it is used by the NAS to
 determine whether the user's response, when entered, should be
 echoed.
 The supported values are listed in [RADIUSTypes].  The following list
 is informational:
    0  No Echo
    1  Echo

5.4. CHAP-Auth AVP

 The CHAP-Auth AVP (AVP Code 402) is of type Grouped and contains the
 information necessary to authenticate a user using the PPP
 Challenge-Handshake Authentication Protocol (CHAP) [PPPCHAP].  If the
 CHAP-Auth AVP is found in a message, the CHAP-Challenge AVP MUST be
 present as well.  The optional AVPs containing the CHAP response
 depend upon the value of the CHAP-Algorithm AVP.  The grouped AVP has
 the following ABNF grammar:
    CHAP-Auth  ::= < AVP Header: 402 >
                   { CHAP-Algorithm }
                   { CHAP-Ident }
                   [ CHAP-Response ]
                 * [ AVP ]

Calhoun, et al. Standards Track [Page 27] RFC 4005 Diameter Network Access Server Application August 2005

5.5. CHAP-Algorithm AVP

 The CHAP-Algorithm AVP (AVP Code 403) is of type Enumerated and
 contains the algorithm identifier used in the computation of the CHAP
 response [PPPCHAP].  The following values are currently supported:
    CHAP with MD5       5
       The CHAP response is computed by using the procedure described
       in [PPPCHAP].  This algorithm requires that the CHAP-Response
       AVP MUST be present in the CHAP-Auth AVP.

5.6. CHAP-Ident AVP

 The CHAP-Ident AVP (AVP Code 404) is of type OctetString and contains
 the 1 octet CHAP Identifier used in the computation of the CHAP
 response [PPPCHAP].

5.7. CHAP-Response AVP

 The CHAP-Response AVP (AVP Code 405) is of type OctetString and
 contains the 16 octet authentication data provided by the user in
 response to the CHAP challenge [PPPCHAP].

5.8. CHAP-Challenge AVP

 The CHAP-Challenge AVP (AVP Code 60) is of type OctetString and
 contains the CHAP Challenge sent by the NAS to the CHAP peer
 [PPPCHAP].

5.9. ARAP-Password AVP

 The ARAP-Password AVP (AVP Code 70) is of type OctetString and is
 only present when the Framed-Protocol AVP (see section 6.10.1) is
 included in the message and is set to ARAP.  This AVP MUST NOT be
 present if either the User-Password or the CHAP-Auth AVP is present.
 See [RADIUSExt] for more information on the contents of this AVP.

5.10. ARAP-Challenge-Response AVP

 The ARAP-Challenge-Response AVP (AVP Code 84) is of type OctetString
 and is only present when the Framed-Protocol AVP (see section 6.10.1)
 is included in the message and is set to ARAP.  This AVP contains an
 8 octet response to the dial-in client's challenge.  The RADIUS
 server calculates this value by taking the dial-in client's challenge
 from the high-order 8 octets of the ARAP-Password AVP and performing
 DES encryption on this value with the authenticating user's password

Calhoun, et al. Standards Track [Page 28] RFC 4005 Diameter Network Access Server Application August 2005

 as the key.  If the user's password is fewer than 8 octets in length,
 the password is padded at the end with NULL octets to a length of 8
 before it is used as a key.

5.11. ARAP-Security AVP

 The ARAP-Security AVP (AVP Code 73) is of type Unsigned32 and MAY be
 present in the AA-Answer message if the Framed-Protocol AVP (see
 section 6.10.1) is set to the value of ARAP, and the Result-Code AVP
 is set to DIAMETER_MULTI_ROUND_AUTH.  See [RADIUSExt] for more
 information on the format of this AVP.

5.12. ARAP-Security-Data AVP

 The ARAP-Security AVP (AVP Code 74) is of type OctetString and MAY be
 present in the AA-Request or AA-Answer message if the Framed-Protocol
 AVP is set to the value of ARAP, and the Result-Code AVP is set to
 DIAMETER_MULTI_ROUND_AUTH.  This AVP contains the security module
 challenge or response associated with the ARAP Security Module
 specified in ARAP-Security.

6. NAS Authorization AVPs

 This section contains the authorization AVPs supported in the NAS
 Application.  The Service-Type AVP SHOULD be present in all messages,
 and, based on its value, additional AVPs defined in this section and
 in section 7 MAY be present.
 Due to space constraints, the short-form IPFltrRule is used to
 represent IPFilterRule, and QoSFltrRule is used for QoSFilterRule.
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT|  NOT|Encr|
 -----------------------------------------|----+-----+----+-----|----|
 Service-Type       6   6.1    Enumerated | M  |  P  |    |  V  | Y  |
 Callback-Number   19   6.2    UTF8String | M  |  P  |    |  V  | Y  |
 Callback-Id       20   6.3    UTF8String | M  |  P  |    |  V  | Y  |
 Idle-Timeout      28   6.4    Unsigned32 | M  |  P  |    |  V  | Y  |
 Port-Limit        62   6.5    Unsigned32 | M  |  P  |    |  V  | Y  |
 NAS-Filter-Rule  400   6.6    IPFltrRule | M  |  P  |    |  V  | Y  |
 Filter-Id         11   6.7    UTF8String | M  |  P  |    |  V  | Y  |
 Configuration-    78   6.8    OctetString| M  |     |    | P,V |    |
   Token                                  |    |     |    |     |    |
 QoS-Filter-Rule  407   6.9    QoSFltrRule|    |     |    |     |    |
 Framed-Protocol    7  6.10.1  Enumerated | M  |  P  |    |  V  | Y  |

Calhoun, et al. Standards Track [Page 29] RFC 4005 Diameter Network Access Server Application August 2005

 Framed-Routing    10  6.10.2  Enumerated | M  |  P  |    |  V  | Y  |
 Framed-MTU        12  6.10.3  Unsigned32 | M  |  P  |    |  V  | Y  |
 Framed-           13  6.10.4  Enumerated | M  |  P  |    |  V  | Y  |
   Compression                            |    |     |    |     |    |
 Framed-IP-Address  8  6.11.1  OctetString| M  |  P  |    |  V  | Y  |
 Framed-IP-Netmask  9  6.11.2  OctetString| M  |  P  |    |  V  | Y  |
 Framed-Route      22  6.11.3  UTF8String | M  |  P  |    |  V  | Y  |
 Framed-Pool       88  6.11.4  OctetString| M  |  P  |    |  V  | Y  |
 Framed-           96  6.11.5  Unsigned64 | M  |  P  |    |  V  | Y  |
   Interface-Id                           |    |     |    |     |    |
 Framed-IPv6-      97  6.11.6  OctetString| M  |  P  |    |  V  | Y  |
   Prefix                                 |    |     |    |     |    |
 Framed-IPv6-      99  6.11.7  UTF8String | M  |  P  |    |  V  | Y  |
   Route                                  |    |     |    |     |    |
 Framed-IPv6-Pool 100  6.11.8  OctetString| M  |  P  |    |  V  | Y  |
 Framed-IPX-       23  6.12.1  UTF8String | M  |  P  |    |  V  | Y  |
   Network                                |    |     |    |     |    |
 Framed-Appletalk- 37  6.13.1  Unsigned32 | M  |  P  |    |  V  | Y  |
   Link                                   |    |     |    |     |    |
 Framed-Appletalk- 38  6.13.2  Unsigned32 | M  |  P  |    |  V  | Y  |
   Network                                |    |     |    |     |    |
 Framed-Appletalk- 39  6.13.3  OctetString| M  |  P  |    |  V  | Y  |
   Zone                                   |    |     |    |     |    |
 ARAP-Features     71  6.14.1  OctetString| M  |  P  |    |  V  | Y  |
 ARAP-Zone-Access  72  6.14.2  Enumerated | M  |  P  |    |  V  | Y  |
 Login-IP-Host     14  6.15.1  OctetString| M  |  P  |    |  V  | Y  |
 Login-IPv6-Host   98  6.15.2  OctetString| M  |  P  |    |  V  | Y  |
 Login-Service     15  6.15.3  Enumerated | M  |  P  |    |  V  | Y  |
 Login-TCP-Port    16  6.16.1  Unsigned32 | M  |  P  |    |  V  | Y  |
 Login-LAT-Service 34  6.17.1  OctetString| M  |  P  |    |  V  | Y  |
 Login-LAT-Node    35  6.17.2  OctetString| M  |  P  |    |  V  | Y  |
 Login-LAT-Group   36  6.17.3  OctetString| M  |  P  |    |  V  | Y  |
 Login-LAT-Port    63  6.17.4  OctetString| M  |  P  |    |  V  | Y  |
 -----------------------------------------|----+-----+----+-----|----|

6.1. Service-Type AVP

 The Service-Type AVP (AVP Code 6) is of type Enumerated and contains
 the type of service the user has requested or the type of service to
 be provided.  One such AVP MAY be present in an authentication and/or
 authorization request or response.  A NAS is not required to
 implement all of these service types.  It MUST treat unknown or
 unsupported Service-Types received in a response as a failure and end
 the session with a DIAMETER_INVALID_AVP_VALUE Result-Code.
 When used in a request, the Service-Type AVP SHOULD be considered a
 hint to the server that the NAS believes the user would prefer the
 kind of service indicated.  The server is not required to honor the

Calhoun, et al. Standards Track [Page 30] RFC 4005 Diameter Network Access Server Application August 2005

 hint.  Furthermore, if the service specified by the server is
 supported, but not compatible with the current mode of access, the
 NAS MUST fail to start the session.  The NAS MUST also generate the
 appropriate error message(s).
 The following values have been defined for the Service-Type AVP.  The
 complete list of defined values can be found in [RADIUS] and
 [RADIUSTypes].  The following list is informational:
     1  Login
     2  Framed
     3  Callback Login
     4  Callback Framed
     5  Outbound
     6  Administrative
     7  NAS Prompt
     8  Authenticate Only
     9  Callback NAS Prompt
    10  Call Check
    11  Callback Administrative
    12  Voice
    13  Fax
    14  Modem Relay
    15  IAPP-Register   [IEEE 802.11f]
    16  IAPP-AP-Check   [IEEE 802.11f]
    17  Authorize Only  [RADDynAuth]
 The following values are further qualified:
    Login               1
       The user should be connected to a host.  The message MAY
       include additional AVPs defined in sections 6.16 or 6.17.
    Framed              2
       A Framed Protocol, such as PPP or SLIP, should be started for
       the User.  The message MAY include additional AVPs defined in
       section 6.10, or section 7 for tunneling services.
    Callback Login      3
       The user should be disconnected and called back, then connected
       to a host.  The message MAY include additional AVPs defined in
       this section.
    Callback Framed     4
       The user should be disconnected and called back, and then a
       Framed Protocol, such as PPP or SLIP, should be started for the
       User.  The message MAY include additional AVPs defined in
       section 6.10, or in section 7 for tunneling services.

Calhoun, et al. Standards Track [Page 31] RFC 4005 Diameter Network Access Server Application August 2005

6.2. Callback-Number AVP

 The Callback-Number AVP (AVP Code 19) is of type UTF8String and
 contains a dialing string to be used for callback.  It MAY be used in
 an authentication and/or authorization request as a hint to the
 server that a Callback service is desired, but the server is not
 required to honor the hint in the corresponding response.
 The codification of this field's allowed usage range is outside the
 scope of this specification.

6.3. Callback-Id AVP

 The Callback-Id AVP (AVP Code 20) is of type UTF8String and contains
 the name of a place to be called, to be interpreted by the NAS.  This
 AVP MAY be present in an authentication and/or authorization
 response.
 This AVP is not roaming-friendly as it assumes that the Callback-Id
 is configured on the NAS.  Using the Callback-Number AVP therefore
 preferable.

6.4. Idle-Timeout AVP

 The Idle-Timeout AVP (AVP Code 28) is of type Unsigned32 and sets the
 maximum number of consecutive seconds of idle connection allowable to
 the user before termination of the session or before a prompt is
 issued.  The default is none, or system specific.

6.5. Port-Limit AVP

 The Port-Limit AVP (AVP Code 62) is of type Unsigned32 and sets the
 maximum number of ports the NAS provides to the user.  It MAY be used
 in an authentication and/or authorization request as a hint to the
 server that multilink PPP [PPPMP] service is desired, but the server
 is not required to honor the hint in the corresponding response.

6.6. NAS-Filter-Rule AVP

 The NAS-Filter-Rule AVP (AVP Code 400) is of type IPFilterRule and
 provides filter rules that need to be configured on the NAS for the
 user.  One or more of these AVPs MAY be present in an authorization
 response.

Calhoun, et al. Standards Track [Page 32] RFC 4005 Diameter Network Access Server Application August 2005

6.7. Filter-Id AVP

 The Filter-Id AVP (AVP Code 11) is of type UTF8String and contains
 the name of the filter list for this user.  Zero or more Filter-Id
 AVPs MAY be sent in an authorization answer.
 Identifying a filter list by name allows the filter to be used on
 different NASes without regard to filter-list implementation details.
 However, this AVP is not roaming friendly, as filter naming differs
 from one service provider to another.
 In non-RADIUS environments, it is RECOMMENDED that the NAS-Filter-
 Rule AVP be used instead.

6.8. Configuration-Token AVP

 The Configuration-Token AVP (AVP Code 78) is of type OctetString and
 is sent by a Diameter Server to a Diameter Proxy Agent or Translation
 Agent in an AA-Answer command to indicate a type of user profile to
 be used.  It should not be sent to a Diameter Client (NAS).
 The format of the Data field of this AVP is site specific.

6.9. QoS-Filter-Rule AVP

 The QoS-Filter-Rule AVP (AVP Code 407) is of type QoSFilterRule and
 provides QoS filter rules that need to be configured on the NAS for
 the user.  One or more such AVPs MAY be present in an authorization
 response.
 Note: Due to an editorial mistake in [BASE], only the AVP format is
 discussed.  The complete QoSFilterRule definition was not included.
 It is reprinted here for clarification.
 QoSFilterRule
    The QosFilterRule format is derived from the OctetString AVP Base
    Format.  It uses the ASCII charset.  Packets may be marked or
    metered based on the following information:
       Direction                          (in or out)
       Source and destination IP address  (possibly masked)
       Protocol
       Source and destination port        (lists or ranges)
       DSCP values                        (no mask or range)
    Rules for the appropriate direction are evaluated in order; the
    first matched rule terminates the evaluation.  Each packet is

Calhoun, et al. Standards Track [Page 33] RFC 4005 Diameter Network Access Server Application August 2005

    evaluated once.  If no rule matches, the packet is treated as best
    effort.  An access device unable to interpret or apply a QoS rule
    SHOULD NOT terminate the session.
 QoSFilterRule filters MUST follow the following format:
    action dir proto from src to dst [options]
              tag    - Mark packet with a specific DSCP
                       [DIFFSERV].  The DSCP option MUST be
                       included.
              meter  - Meter traffic.  The metering options
                       MUST be included.
 dir           The format is as described under IPFilterRule.
 proto         The format is as described under IPFilterRule.
 src and dst   The format is as described under IPFilterRule.
       options:
       DSCP <color>
             Color values as defined in [DIFFSERV].  Exact
             matching of DSCP values is required (no masks or
             ranges).
       metering <rate> <color_under> <color_over>
             The metering option provides Assured Forwarding,
             as defined in [DIFFSERVAF], and MUST be present
             if the action is set to meter.  The rate option is
             the throughput, in bits per second, used
             by the access device to mark packets.  Traffic
             over the rate is marked with the color_over
             codepoint, and traffic under the rate is marked
             with the color_under codepoint.  The color_under
             and color_over options contain the drop
             preferences and MUST conform to the recommended
             codepoint keywords described in [DIFFSERVAF]
             (e.g., AF13).
             The metering option also supports the strict
             limit on traffic required by Expedited
             Forwarding, as defined in [DIFFSERVEF].  The
             color_over option may contain the keyword "drop"
             to prevent forwarding of traffic that exceeds the
             rate parameter.

Calhoun, et al. Standards Track [Page 34] RFC 4005 Diameter Network Access Server Application August 2005

       The rule syntax is a modified subset of ipfw(8) from FreeBSD,
       and the ipfw.c code may provide a useful base for
       implementations.

6.10. Framed Access Authorization AVPs

 This section lists the authorization AVPs necessary to
 support framed access, such as PPP and SLIP.  AVPs defined in this
 section MAY be present in a message if the Service-Type AVP was set
 to "Framed" or "Callback Framed".

6.10.1. Framed-Protocol AVP

 The Framed-Protocol AVP (AVP Code 7) is of type Enumerated and
 contains the framing to be used for framed access.  This AVP MAY be
 present in both requests and responses.  The supported values are
 listed in [RADIUSTypes].  The following list is informational:
    1  PPP
    2  SLIP
    3  AppleTalk Remote Access Protocol (ARAP)
    4  Gandalf proprietary SingleLink/MultiLink protocol
    5  Xylogics proprietary IPX/SLIP
    6  X.75 Synchronous

6.10.2. Framed-Routing AVP

 The Framed-Routing AVP (AVP Code 10) is of type Enumerated and
 contains the routing method for the user when the user is a router to
 a network.  This AVP SHOULD only be present in authorization
 responses.  The supported values are listed in [RADIUSTypes].  The
 following list is informational:
    0  None
    1  Send routing packets
    2  Listen for routing packets
    3  Send and Listen

6.10.3. Framed-MTU AVP

 The Framed-MTU AVP (AVP Code 12) is of type Unsigned32 and contains
 the Maximum Transmission Unit to be configured for the user, when it
 is not negotiated by some other means (such as PPP).  This AVP SHOULD
 only be present in authorization responses.  The MTU value MUST be in
 the range from 64 to 65535.

Calhoun, et al. Standards Track [Page 35] RFC 4005 Diameter Network Access Server Application August 2005

6.10.4. Framed-Compression AVP

 The Framed-Compression AVP (AVP Code 13) is of type Enumerated and
 contains the compression protocol to be used for the link.  It MAY be
 used in an authorization request as a hint to the server that a
 specific compression type is desired, but the server is not required
 to honor the hint in the corresponding response.
 More than one compression protocol AVP MAY be sent.  The NAS is
 responsible for applying the proper compression protocol to the
 appropriate link traffic.
 The supported values are listed in [RADIUSTypes].  The following list
 is informational:
    0  None
    1  VJ TCP/IP header compression
    2  IPX header compression
    3  Stac-LZS compression

6.11. IP Access Authorization AVPs

 The AVPs defined in this section are used when the user requests, or
 is being granted, access service to IP.

6.11.1. Framed-IP-Address AVP

 The Framed-IP-Address AVP (AVP Code 8) [RADIUS] is of type
 OctetString and contains an IPv4 address of the type specified in the
 attribute value to be configured for the user.  It MAY be used in an
 authorization request as a hint to the server that a specific address
 is desired, but the server is not required to honor the hint in the
 corresponding response.
 Two values have special significance: 0xFFFFFFFF and 0xFFFFFFFE.  The
 value 0xFFFFFFFF indicates that the NAS should allow the user to
 select an address (i.e., negotiated).  The value 0xFFFFFFFE indicates
 that the NAS should select an address for the user (e.g., assigned
 from a pool of addresses kept by the NAS).

6.11.2. Framed-IP-Netmask AVP

 The Framed-IP-Netmask AVP (AVP Code 9) is of type OctetString and
 contains the four octets of the IPv4 netmask to be configured for the
 user when the user is a router to a network.  It MAY be used in an
 authorization request as a hint to the server that a specific netmask

Calhoun, et al. Standards Track [Page 36] RFC 4005 Diameter Network Access Server Application August 2005

 is desired, but the server is not required to honor the hint in the
 corresponding response.  This AVP MUST be present in a response if
 the request included this AVP with a value of 0xFFFFFFFF.

6.11.3. Framed-Route AVP

 The Framed-Route AVP (AVP Code 22) is of type UTF8String and contains
 the ASCII routing information to be configured for the user on the
 NAS.  Zero or more of these AVPs MAY be present in an authorization
 response.
 The string MUST contain a destination prefix in dotted quad form
 optionally followed by a slash and a decimal length specifier stating
 how many high-order bits of the prefix should be used.  This is
 followed by a space, a gateway address in dotted quad form, a space,
 and one or more metrics separated by spaces; for example,
    "192.168.1.0/24 192.168.1.1 1".
 The length specifier may be omitted, in which case it should default
 to 8 bits for class A prefixes, to 16 bits for class B prefixes, and
 to 24 bits for class C prefixes; for example,
    "192.168.1.0 192.168.1.1 1".
 Whenever the gateway address is specified as "0.0.0.0" the IP address
 of the user SHOULD be used as the gateway address.

6.11.4. Framed-Pool AVP

 The Framed-Pool AVP (AVP Code 88) is of type OctetString and contains
 the name of an assigned address pool that SHOULD be used to assign an
 address for the user.  If a NAS does not support multiple address
 pools, the NAS SHOULD ignore this AVP.  Address pools are usually
 used for IP addresses but can be used for other protocols if the NAS
 supports pools for those protocols.
 Although specified as type OctetString for compatibility with RADIUS
 [RADIUSExt], the encoding of the Data field SHOULD also conform to
 the rules for the UTF8String Data Format.

6.11.5. Framed-Interface-Id AVP

 The Framed-Interface-Id AVP (AVP Code 96) is of type Unsigned64 and
 contains the IPv6 interface identifier to be configured for the user.
 It MAY be used in authorization requests as a hint to the server that
 a specific interface id is desired, but the server is not required to
 honor the hint in the corresponding response.

Calhoun, et al. Standards Track [Page 37] RFC 4005 Diameter Network Access Server Application August 2005

6.11.6. Framed-IPv6-Prefix AVP

 The Framed-IPv6-Prefix AVP (AVP Code 97) is of type OctetString and
 contains the IPv6 prefix to be configured for the user.  One or more
 AVPs MAY be used in authorization requests as a hint to the server
 that specific IPv6 prefixes are desired, but the server is not
 required to honor the hint in the corresponding response.

6.11.7. Framed-IPv6-Route AVP

 The Framed-IPv6-Route AVP (AVP Code 99) is of type UTF8String and
 contains the ASCII routing information to be configured for the user
 on the NAS.  Zero or more of these AVPs MAY be present in an
 authorization response.
 The string MUST contain an IPv6 address prefix followed by a slash
 and a decimal length specifier stating how many high order bits of
 the prefix should be used.  This is followed by a space, a gateway
 address in hexadecimal notation, a space, and one or more metrics
 separated by spaces; for example,
    "2000:0:0:106::/64 2000::106:a00:20ff:fe99:a998 1".
 Whenever the gateway address is the IPv6 unspecified address, the IP
 address of the user SHOULD be used as the gateway address, such as
 in:
    "2000:0:0:106::/64 :: 1".

6.11.8. Framed-IPv6-Pool AVP

 The Framed-IPv6-Pool AVP (AVP Code 100) is of type OctetString and
 contains the name of an assigned pool that SHOULD be used to assign
 an IPv6 prefix for the user.  If the access device does not support
 multiple prefix pools, it MUST ignore this AVP.
 Although specified as type OctetString for compatibility with RADIUS
 [RADIUSIPv6], the encoding of the Data field SHOULD also conform to
 the rules for the UTF8String Data Format.

6.12. IPX Access

 The AVPs defined in this section are used when the user requests, or
 is being granted, access to an IPX network service.

Calhoun, et al. Standards Track [Page 38] RFC 4005 Diameter Network Access Server Application August 2005

6.12.1. Framed-IPX-Network AVP

 The Framed-IPX-Network AVP (AVP Code 23) is of type Unsigned32 and
 contains the IPX Network number to be configured for the user.  It
 MAY be used in an authorization request as a hint to the server that
 a specific address is desired, but the server is not required to
 honor the hint in the corresponding response.
 Two addresses have special significance: 0xFFFFFFFF and 0xFFFFFFFE.
 The value 0xFFFFFFFF indicates that the NAS should allow the user to
 select an address (i.e., Negotiated).  The value 0xFFFFFFFE indicates
 that the NAS should select an address for the user (e.g., assign it
 from a pool of one or more IPX networks kept by the NAS).

6.13. AppleTalk Network Access

 The AVPs defined in this section are used when the user requests, or
 is being granted, access to an AppleTalk network [AppleTalk].

6.13.1. Framed-AppleTalk-Link AVP

 The Framed-AppleTalk-Link AVP (AVP Code 37) is of type Unsigned32 and
 contains the AppleTalk network number that should be used for the
 serial link to the user, which is another AppleTalk router.  This AVP
 MUST only be present in an authorization response and is never used
 when the user is not another router.
 Despite the size of the field, values range from 0 to 65,535.  The
 special value of 0 indicates an unnumbered serial link.  A value of 1
 to 65,535 means that the serial line between the NAS and the user
 should be assigned that value as an AppleTalk network number.

6.13.2. Framed-AppleTalk-Network AVP

 The Framed-AppleTalk-Network AVP (AVP Code 38) is of type Unsigned32
 and contains the AppleTalk Network number that the NAS should probe
 to allocate an AppleTalk node for the user.  This AVP MUST only be
 present in an authorization response and is never used when the user
 is not another router.  Multiple instances of this AVP indicate that
 the NAS may probe, using any of the network numbers specified.
 Despite the size of the field, values range from 0 to 65,535.  The
 special value 0 indicates that the NAS should assign a network for
 the user, using its default cable range.  A value between 1 and
 65,535 (inclusive) indicates to the AppleTalk Network that the NAS
 should probe to find an address for the user.

Calhoun, et al. Standards Track [Page 39] RFC 4005 Diameter Network Access Server Application August 2005

6.13.3. Framed-AppleTalk-Zone AVP

 The Framed-AppleTalk-Zone AVP (AVP Code 39) is of type OctetString
 and contains the AppleTalk Default Zone to be used for this user.
 This AVP MUST only be present in an authorization response.  Multiple
 instances of this AVP in the same message are not allowed.
 The codification of this field's allowed range is outside the scope
 of this specification.

6.14. AppleTalk Remote Access

 The AVPs defined in this section are used when the user requests, or
 is being granted, access to the AppleTalk network via the AppleTalk
 Remote Access Protocol [ARAP].  They are only present if the Framed-
 Protocol AVP (see section 6.10.1) is set to ARAP.  Section 2.2 of RFC
 2869 [RADIUSExt] describes the operational use of these attributes.

6.14.1. ARAP-Features AVP

 The ARAP-Features AVP (AVP Code 71) is of type OctetString and MAY be
 present in the AA-Accept message if the Framed-Protocol AVP is set to
 the value of ARAP.  See [RADIUSExt] for more information about the
 format of this AVP.

6.14.2. ARAP-Zone-Access AVP

 The ARAP-Zone-Access AVP (AVP Code 72) is of type Enumerated and MAY
 be present in the AA-Accept message if the Framed-Protocol AVP is set
 to the value of ARAP.
 The supported values are listed in [RADIUSTypes] and defined in
 [RADIUSExt].

6.15. Non-Framed Access Authorization AVPs

 This section contains the authorization AVPs that are needed to
 support terminal server functionality.  AVPs defined in this section
 MAY be present in a message if the Service-Type AVP was set to
 "Login" or "Callback Login".

6.15.1. Login-IP-Host AVP

 The Login-IP-Host AVP (AVP Code 14) [RADIUS] is of type OctetString
 and contains the IPv4 address of a host with which to connect the
 user when the Login-Service AVP is included.  It MAY be used in an
 AA-Request command as a hint to the Diameter Server that a specific

Calhoun, et al. Standards Track [Page 40] RFC 4005 Diameter Network Access Server Application August 2005

 host is desired, but the Diameter Server is not required to honor the
 hint in the AA-Answer.
 Two addresses have special significance: all ones and 0.  The value
 of all ones indicates that the NAS SHOULD allow the user to select an
 address.  The value 0 indicates that the NAS SHOULD select a host to
 connect the user to.

6.15.2. Login-IPv6-Host AVP

 The Login-IPv6-Host AVP (AVP Code 98) [RADIUSIPv6] is of type
 OctetString and contains the IPv6 address of a host with which to
 connect the user when the Login-Service AVP is included.  It MAY be
 used in an AA-Request command as a hint to the Diameter Server that a
 specific host is desired, but the Diameter Server is not required to
 honor the hint in the AA-Answer.
 Two addresses have special significance:
 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF and 0.  The value
 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF indicates that the NAS SHOULD
 allow the user to select an address.  The value 0 indicates that the
 NAS SHOULD select a host to connect the user to.

6.15.3. Login-Service AVP

 The Login-Service AVP (AVP Code 15) is of type Enumerated and
 contains the service that should be used to connect the user to the
 login host.  This AVP SHOULD only be present in authorization
 responses.
 The supported values are listed in [RADIUSTypes].  The following list
 is informational:
    0  Telnet
    1  Rlogin
    2  TCP Clear
    3  PortMaster (proprietary)
    4  LAT
    5  X25-PAD
    6  X25-T3POS
    8  TCP Clear Quiet (suppresses any NAS-generated connect
                string)

Calhoun, et al. Standards Track [Page 41] RFC 4005 Diameter Network Access Server Application August 2005

6.16. TCP Services

 The AVPs described in this section MAY be present if the Login-
 Service AVP is set to Telnet, Rlogin, TCP Clear, or TCP Clear Quiet.

6.16.1. Login-TCP-Port AVP

 The Login-TCP-Port AVP (AVP Code 16) is of type Unsigned32 and
 contains the TCP port with which the user is to be connected when the
 Login-Service AVP is also present.  This AVP SHOULD only be present
 in authorization responses.  The value MUST NOT be greater than
 65,535.

6.17. LAT Services

 The AVPs described in this section MAY be present if the Login-
 Service AVP is set to LAT [LAT].

6.17.1. Login-LAT-Service AVP

 The Login-LAT-Service AVP (AVP Code 34) is of type OctetString and
 contains the system with which the user is to be connected by LAT.
 It MAY be used in an authorization request as a hint to the server
 that a specific service is desired, but the server is not required to
 honor the hint in the corresponding response.  This AVP MUST only be
 present in the response if the Login-Service AVP states that LAT is
 desired.
 Administrators use this service attribute when dealing with clustered
 systems, such as a VAX or Alpha cluster.  In these environments,
 several different time-sharing hosts share the same resources (disks,
 printers, etc.), and administrators often configure each host to
 offer access (service) to each of the shared resources.  In this
 case, each host in the cluster advertises its services through LAT
 broadcasts.
 Sophisticated users often know which service providers (machines) are
 faster and tend to use a node name when initiating a LAT connection.
 Some administrators want particular users to use certain machines as
 a primitive form of load balancing (although LAT knows how to do load
 balancing itself).
 The String field contains the identity of the LAT service to use.
 The LAT Architecture allows this string to contain $ (dollar), -
 (hyphen), . (period), _ (underscore), numerics, upper- and lowercase
 alphabetics, and the ISO Latin-1 character set extension [ISOLatin].
 All LAT string comparisons are case insensitive.

Calhoun, et al. Standards Track [Page 42] RFC 4005 Diameter Network Access Server Application August 2005

6.17.2. Login-LAT-Node AVP

 The Login-LAT-Node AVP (AVP Code 35) is of type OctetString and
 contains the Node with which the user is to be automatically
 connected by LAT.  It MAY be used in an authorization request as a
 hint to the server that a specific LAT node is desired, but the
 server is not required to honor the hint in the corresponding
 response.  This AVP MUST only be present in a response if the Login-
 Service-Type AVP is set to LAT.
 The String field contains the identity of the LAT service to use.
 The LAT Architecture allows this string to contain $ (dollar), -
 (hyphen), . (period), _ (underscore), numerics, upper- and lowercase
 alphabetics, and the ISO Latin-1 character set extension [ISOLatin].
 All LAT string comparisons are case insensitive.

6.17.3. Login-LAT-Group AVP

 The Login-LAT-Group AVP (AVP Code 36) is of type OctetString and
 contains a string identifying the LAT group codes this user is
 authorized to use.  It MAY be used in an authorization request as a
 hint to the server that a specific group is desired, but the server
 is not required to honor the hint in the corresponding response.
 This AVP MUST only be present in a response if the Login-Service-Type
 AVP is set to LAT.
 LAT supports 256 different group codes, which LAT uses as a form of
 access rights.  LAT encodes the group codes as a 256-bit bitmap.
 Administrators can assign one or more of the group code bits at the
 LAT service provider; it will only accept LAT connections that have
 these group codes set in the bitmap.  The administrators assign a
 bitmap of authorized group codes to each user.  LAT gets these from
 the operating system and uses them in its requests to the service
 providers.
 The codification of the range of allowed usage of this field is
 outside the scope of this specification.

6.17.4. Login-LAT-Port AVP

 The Login-LAT-Port AVP (AVP Code 63) is of type OctetString and
 contains the Port with which the user is to be connected by LAT.  It
 MAY be used in an authorization request as a hint to the server that
 a specific port is desired, but the server is not required to honor
 the hint in the corresponding response.  This AVP MUST only be
 present in a response if the Login-Service-Type AVP is set to LAT.

Calhoun, et al. Standards Track [Page 43] RFC 4005 Diameter Network Access Server Application August 2005

 The String field contains the identity of the LAT service to use.
 The LAT Architecture allows this string to contain $ (dollar), -
 (hyphen), . (period), _ (underscore), numerics, upper- and lower-case
 alphabetics, and the ISO Latin-1 character set extension [ISOLatin].
 All LAT string comparisons are case insensitive.

7. NAS Tunneling

 Some NASes support compulsory tunnel services in which the incoming
 connection data is conveyed by an encapsulation method to a gateway
 elsewhere in the network.  This is typically transparent to the
 service user, and the tunnel characteristics may be described by the
 remote AAA server, based on the user's authorization information.
 Several tunnel characteristics may be returned, and the NAS
 implementation may choose one [RADTunnels], [RADTunlAcct].
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT| NOT |Encr|
 -----------------------------------------|----+-----+----+-----|----|
 Tunneling        401   7.1    Grouped    | M  |  P  |    |  V  | N  |
 Tunnel-Type       64   7.2    Enumerated | M  |  P  |    |  V  | Y  |
 Tunnel-Medium-    65   7.3    Enumerated | M  |  P  |    |  V  | Y  |
   Type                                   |    |     |    |     |    |
 Tunnel-Client-    66   7.4    UTF8String | M  |  P  |    |  V  | Y  |
   Endpoint                               |    |     |    |     |    |
 Tunnel-Server-    67   7.5    UTF8String | M  |  P  |    |  V  | Y  |
   Endpoint                               |    |     |    |     |    |
 Tunnel-Password   69   7.6    OctetString| M  |  P  |    |  V  | Y  |
 Tunnel-Private-   81   7.7    OctetString| M  |  P  |    |  V  | Y  |
   Group-Id                               |    |     |    |     |    |
 Tunnel-           82   7.8    OctetString| M  |  P  |    |  V  | Y  |
   Assignment-Id                          |    |     |    |     |    |
 Tunnel-Preference 83   7.9    Unsigned32 | M  |  P  |    |  V  | Y  |
 Tunnel-Client-    90   7.10   UTF8String | M  |  P  |    |  V  | Y  |
   Auth-Id                                |    |     |    |     |    |
 Tunnel-Server-    91   7.11   UTF8String | M  |  P  |    |  V  | Y  |
   Auth-Id                                |    |     |    |     |    |
 -----------------------------------------|----+-----+----+-----|----|

7.1. Tunneling AVP

 The Tunneling AVP (AVP Code 401) is of type Grouped and contains the
 following AVPs, used to describe a compulsory tunnel service:
 [RADTunnels], [RADTunlAcct].  Its data field has the following ABNF
 grammar:

Calhoun, et al. Standards Track [Page 44] RFC 4005 Diameter Network Access Server Application August 2005

    Tunneling     ::= < AVP Header: 401 >
                      { Tunnel-Type }
                      { Tunnel-Medium-Type }
                      { Tunnel-Client-Endpoint }
                      { Tunnel-Server-Endpoint }
                      [ Tunnel-Preference ]
                      [ Tunnel-Client-Auth-Id ]
                      [ Tunnel-Server-Auth-Id ]
                      [ Tunnel-Assignment-Id ]
                      [ Tunnel-Password ]
                      [ Tunnel-Private-Group-Id ]

7.2. Tunnel-Type AVP

 The Tunnel-Type AVP (AVP Code 64) is of type Enumerated and contains
 the tunneling protocol(s) to be used (in the case of a tunnel
 initiator) or in use (in the case of a tunnel terminator).  It MAY be
 used in an authorization request as a hint to the server that a
 specific tunnel type is desired, but the server is not required to
 honor the hint in the corresponding response.
 The Tunnel-Type AVP SHOULD also be included in Accounting-Request
 messages.
 A tunnel initiator is not required to implement any of these tunnel
 types.  If a tunnel initiator receives a response that contains only
 unknown or unsupported Tunnel-Types, the tunnel initiator MUST behave
 as though a response were received with the Result-Code indicating a
 failure.
 The supported values are listed in [RADIUSTypes].  The following list
 is informational:
     1  Point-to-Point Tunneling Protocol (PPTP)
     2  Layer Two Forwarding (L2F)
     3  Layer Two Tunneling Protocol (L2TP)
     4  Ascend Tunnel Management Protocol (ATMP)
     5  Virtual Tunneling Protocol (VTP)
     6  IP Authentication Header in the Tunnel-mode (AH)
     7  IP-in-IP Encapsulation (IP-IP)
     8  Minimal IP-in-IP Encapsulation (MIN-IP-IP)
     9  IP Encapsulating Security Payload in the Tunnel-mode (ESP)
    10  Generic Route Encapsulation (GRE)
    11  Bay Dial Virtual Services (DVS)
    12  IP-in-IP Tunneling
    13  Virtual LANs (VLAN)

Calhoun, et al. Standards Track [Page 45] RFC 4005 Diameter Network Access Server Application August 2005

7.3. Tunnel-Medium-Type AVP

 The Tunnel-Medium-Type AVP (AVP Code 65) is of type Enumerated and
 contains the transport medium to use when creating a tunnel for
 protocols (such as L2TP) that can operate over multiple transports.
 It MAY be used in an authorization request as a hint to the server
 that a specific medium is desired, but the server is not required to
 honor the hint in the corresponding response.
 The supported values are listed in [RADIUSTypes].  The following list
 is informational:
     1  IPv4 (IP version 4)
     2  IPv6 (IP version 6)
     3  NSAP
     4  HDLC (8-bit multidrop)
     5  BBN 1822
     6  802 (includes all 802 media plus Ethernet "canonical
                  format")
     7  E.163 (POTS)
     8  E.164 (SMDS, Frame Relay, ATM)
     9  F.69 (Telex)
    10  X.121 (X.25, Frame Relay)
    11  IPX
    12  Appletalk
    13  Decnet IV
    14  Banyan Vines
    15  E.164 with NSAP format subaddress

7.4. Tunnel-Client-Endpoint AVP

 The Tunnel-Client-Endpoint AVP (AVP Code 66) is of type UTF8String
 and contains the address of the initiator end of the tunnel.  It MAY
 be used in an authorization request as a hint to the server that a
 specific endpoint is desired, but the server is not required to honor
 the hint in the corresponding response.
 This AVP SHOULD be included in the corresponding Accounting-Request
 messages, in which case it indicates the address from which the
 tunnel was initiated.  This AVP, along with the Tunnel-Server-
 Endpoint and Session-Id AVP [BASE], MAY be used to provide a globally
 unique means to identify a tunnel for accounting and auditing
 purposes.
 If Tunnel-Medium-Type is IPv4 (1), then this string is either the
 fully qualified domain name (FQDN) of the tunnel client machine, or a

Calhoun, et al. Standards Track [Page 46] RFC 4005 Diameter Network Access Server Application August 2005

 "dotted-decimal" IP address.  Implementations MUST support the
 dotted-decimal format and SHOULD support the FQDN format for IP
 addresses.
 If Tunnel-Medium-Type is IPv6 (2), then this string is either the
 FQDN of the tunnel client machine, or a text representation of the
 address in either the preferred or alternate form [IPv6Addr].
 Conforming implementations MUST support the preferred form and SHOULD
 support both the alternate text form and the FQDN format for IPv6
 addresses.
 If Tunnel-Medium-Type is neither IPv4 nor IPv6, then this string is a
 tag referring to configuration data local to the Diameter client that
 describes the interface or medium-specific client address to use.

7.5. Tunnel-Server-Endpoint AVP

 The Tunnel-Server-Endpoint AVP (AVP Code 67) is of type UTF8String
 and contains the address of the server end of the tunnel.  It MAY be
 used in an authorization request as a hint to the server that a
 specific endpoint is desired, but the server is not required to honor
 the hint in the corresponding response.
 This AVP SHOULD be included in the corresponding Accounting-Request
 messages, in which case it indicates the address from which the
 tunnel was initiated.  This AVP, along with the Tunnel-Client-
 Endpoint and Session-Id AVP [BASE], MAY be used to provide a globally
 unique means to identify a tunnel for accounting and auditing
 purposes.
 If Tunnel-Medium-Type is IPv4 (1), then this string is either the
 fully qualified domain name (FQDN) of the tunnel server machine, or a
 "dotted-decimal" IP address.  Implementations MUST support the
 dotted-decimal format and SHOULD support the FQDN format for IP
 addresses.
 If Tunnel-Medium-Type is IPv6 (2), then this string is either the
 FQDN of the tunnel server machine, or a text representation of the
 address in either the preferred or alternate form [IPv6Addr].
 Implementations MUST support the preferred form and SHOULD support
 both the alternate text form and the FQDN format for IPv6 addresses.
 If Tunnel-Medium-Type is not IPv4 or IPv6, this string is a tag
 referring to configuration data local to the Diameter client that
 describes the interface or medium-specific server address to use.

Calhoun, et al. Standards Track [Page 47] RFC 4005 Diameter Network Access Server Application August 2005

7.6. Tunnel-Password AVP

 The Tunnel-Password AVP (AVP Code 69) is of type OctetString and may
 contain a password to be used to authenticate to a remote server.
 The Tunnel-Password AVP contains sensitive information.  This value
 is not protected in the same manner as RADIUS [RADTunnels].
 As required in [BASE], Diameter messages are encrypted by using IPsec
 or TLS.  The Tunnel-Password AVP SHOULD NOT be used in untrusted
 proxy environments without encrypting it by using end-to-end security
 techniques, such as CMS Security [DiamCMS].

7.7. Tunnel-Private-Group-Id AVP

 The Tunnel-Private-Group-Id AVP (AVP Code 81) is of type OctetString
 and contains the group Id for a particular tunneled session.  The
 Tunnel-Private-Group-Id AVP MAY be included in an authorization
 request if the tunnel initiator can predetermine the group resulting
 from a particular connection.  It SHOULD be included in the
 authorization response if this tunnel session is to be treated as
 belonging to a particular private group.  Private groups may be used
 to associate a tunneled session with a particular group of users.
 For example, it MAY be used to facilitate routing of unregistered IP
 addresses through a particular interface.  This AVP SHOULD be
 included in the Accounting-Request messages that pertain to the
 tunneled session.

7.8. Tunnel-Assignment-Id AVP

 The Tunnel-Assignment-Id AVP (AVP Code 82) is of type OctetString and
 is used to indicate to the tunnel initiator the particular tunnel to
 which a session is to be assigned.  Some tunneling protocols, such as
 [PPTP] and [L2TP], allow for sessions between the same two tunnel
 endpoints to be multiplexed over the same tunnel and also for a given
 session to use its own dedicated tunnel.  This attribute provides a
 mechanism for Diameter to inform the tunnel initiator (e.g., PAC,
 LAC) whether to assign the session to a multiplexed tunnel or to a
 separate tunnel.  Furthermore, it allows for sessions sharing
 multiplexed tunnels to be assigned to different multiplexed tunnels.
 A particular tunneling implementation may assign differing
 characteristics to particular tunnels.  For example, different
 tunnels may be assigned different QoS parameters.  Such tunnels may
 be used to carry either individual or multiple sessions.  The
 Tunnel-Assignment-Id attribute thus allows the Diameter server to
 indicate that a particular session is to be assigned to a tunnel
 providing an appropriate level of service.  It is expected that any
 QoS-related Diameter tunneling attributes defined in the future

Calhoun, et al. Standards Track [Page 48] RFC 4005 Diameter Network Access Server Application August 2005

 accompanying this one will be associated by the tunnel initiator with
 the Id given by this attribute.  In the meantime, any semantic given
 to a particular Id string is a matter left to local configuration in
 the tunnel initiator.
 The Tunnel-Assignment-Id AVP is of significance only to Diameter and
 the tunnel initiator.  The Id it specifies is only intended to be of
 local use to Diameter and the tunnel initiator.  The Id assigned by
 the tunnel initiator is not conveyed to the tunnel peer.
 This attribute MAY be included in authorization responses.  The
 tunnel initiator receiving this attribute MAY choose to ignore it and
 to assign the session to an arbitrary multiplexed or non-multiplexed
 tunnel between the desired endpoints.  This AVP SHOULD also be
 included in the Accounting-Request messages pertaining to the
 tunneled session.
 If a tunnel initiator supports the Tunnel-Assignment-Id AVP, then it
 should assign a session to a tunnel in the following manner:
  1. If this AVP is present and a tunnel exists between the

specified endpoints with the specified Id, then the session

       should be assigned to that tunnel.
  1. If this AVP is present and no tunnel exists between the

specified endpoints with the specified Id, then a new tunnel

       should be established for the session and the specified Id
       should be associated with the new tunnel.
  1. If this AVP is not present, then the session is assigned to an

unnamed tunnel. If an unnamed tunnel does not yet exist

       between the specified endpoints, then it is established and
       used for this session and for subsequent ones established
       without the Tunnel-Assignment-Id attribute.  A tunnel initiator
       MUST NOT assign a session for which a Tunnel-Assignment-Id AVP
       was not specified to a named tunnel (i.e., one that was
       initiated by a session specifying this AVP).
 Note that the same Id may be used to name different tunnels if these
 tunnels are between different endpoints.

7.9. Tunnel-Preference AVP

 The Tunnel-Preference AVP (AVP Code 83) is of type Unsigned32 and is
 used to identify the relative preference assigned to each tunnel when
 more than one set of tunneling AVPs is returned within separate
 Grouped-AVP AVPs.  It MAY be used in an authorization request as a
 hint to the server that a specific preference is desired, but the

Calhoun, et al. Standards Track [Page 49] RFC 4005 Diameter Network Access Server Application August 2005

 server is not required to honor the hint in the corresponding
 response.
 For example, suppose that AVPs describing two tunnels are returned by
 the server, one with a Tunnel-Type of PPTP and the other with a
 Tunnel-Type of L2TP.  If the tunnel initiator supports only one of
 the Tunnel-Types returned, it will initiate a tunnel of that type.
 If, however, it supports both tunnel protocols, it SHOULD use the
 value of the Tunnel-Preference AVP to decide which tunnel should be
 started.  The tunnel with the lowest numerical value in the Value
 field of this AVP SHOULD be given the highest preference.  The values
 assigned to two or more instances of the Tunnel-Preference AVP within
 a given authorization response MAY be identical.  In this case, the
 tunnel initiator SHOULD use locally configured metrics to decide
 which set of AVPs to use.

7.10. Tunnel-Client-Auth-Id AVP

 The Tunnel-Client-Auth-Id AVP (AVP Code 90) is of type UTF8String and
 specifies the name used by the tunnel initiator during the
 authentication phase of tunnel establishment.  It MAY be used in an
 authorization request as a hint to the server that a specific
 preference is desired, but the server is not required to honor the
 hint in the corresponding response.  This AVP MUST be present in the
 authorization response if an authentication name other than the
 default is desired.  This AVP SHOULD be included in the Accounting-
 Request messages pertaining to the tunneled session.

7.11. Tunnel-Server-Auth-Id AVP

 The Tunnel-Server-Auth-Id AVP (AVP Code 91) is of type UTF8String and
 specifies the name used by the tunnel terminator during the
 authentication phase of tunnel establishment.  It MAY be used in an
 authorization request as a hint to the server that a specific
 preference is desired, but the server is not required to honor the
 hint in the corresponding response.  This AVP MUST be present in the
 authorization response if an authentication name other than the
 default is desired.  This AVP SHOULD be included in the Accounting-
 Request messages pertaining to the tunneled session.

8. NAS Accounting

 Applications implementing this specification use Diameter Accounting,
 as defined in [BASE], and the AVPs in the following section.
 Service-specific AVP usage is defined in the tables in section 10.
 If accounting is active, Accounting Request (ACR) messages SHOULD be
 sent after the completion of any Authentication or Authorization

Calhoun, et al. Standards Track [Page 50] RFC 4005 Diameter Network Access Server Application August 2005

 transaction and at the end of a Session.  The Accounting-Record-Type
 value indicates the type of event.  All other AVPs identify the
 session and provide additional information relevant to the event.
 The successful completion of the first Authentication or
 Authorization transaction SHOULD cause a START_RECORD to be sent.  If
 additional Authentications or Authorizations occur in later
 transactions, the first exchange should generate a START_RECORD, and
 the later an INTERIM_RECORD.  For a given session, there MUST only be
 one set of matching START and STOP records, with any number of
 INTERIM_RECORDS in between, or one EVENT_RECORD indicating the reason
 a session wasn't started.
 The following table describes the AVPs; their AVP Code values, types,
 and possible flag values; and whether the AVP MAY be encrypted.
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT|  NOT|Encr|
 -----------------------------------------|----+-----+----+-----|----|
 Accounting-      363  8.1     Unsigned64 | M  |  P  |    |  V  | Y  |
   Input-Octets                           |    |     |    |     |    |
 Accounting-      364  8.2     Unsigned64 | M  |  P  |    |  V  | Y  |
   Output-Octets                          |    |     |    |     |    |
 Accounting-      365  8.3     Unsigned64 | M  |  P  |    |  V  | Y  |
   Input-Packets                          |    |     |    |     |    |
 Accounting-      366  8.4     Unsigned64 | M  |  P  |    |  V  | Y  |
   Output-Packets                         |    |     |    |     |    |
 Acct-Session-Time 46  8.5     Unsigned32 | M  |  P  |    |  V  | Y  |
 Acct-Authentic    45  8.6     Enumerated | M  |  P  |    |  V  | Y  |
 Acounting-Auth-  406  8.7     Enumerated | M  |  P  |    |  V  | Y  |
   Method                                 |    |     |    |     |    |
 Acct-Delay-Time   41  8.8     Unsigned32 | M  |  P  |    |  V  | Y  |
 Acct-Link-Count   51  8.9     Unsigned32 | M  |  P  |    |  V  | Y  |
 Acct-Tunnel-      68  8.10    OctetString| M  |  P  |    |  V  | Y  |
   Connection                             |    |     |    |     |    |
 Acct-Tunnel-      86  8.11    Unsigned32 | M  |  P  |    |  V  | Y  |
   Packets-Lost                           |    |     |    |     |    |
 -----------------------------------------|----+-----+----+-----|----|

8.1. Accounting-Input-Octets AVP

 The Accounting-Input-Octets AVP (AVP Code 363) is of type Unsigned64
 and contains the number of octets received from the user.

Calhoun, et al. Standards Track [Page 51] RFC 4005 Diameter Network Access Server Application August 2005

 For NAS usage, this AVP indicates how many octets have been received
 from the port in the course of this session.  It can only be present
 in ACR messages with an Accounting-Record-Type of INTERIM_RECORD or
 STOP_RECORD.

8.2. Accounting-Output-Octets AVP

 The Accounting-Output-Octets AVP (AVP Code 364) is of type Unsigned64
 and contains the number of octets sent to the user.
 For NAS usage, this AVP indicates how many octets have been sent to
 the port in the course of this session.  It can only be present in
 ACR messages with an Accounting-Record-Type of INTERIM_RECORD or
 STOP_RECORD.

8.3. Accounting-Input-Packets AVP

 The Accounting-Input-Packets (AVP Code 365) is of type Unsigned64 and
 contains the number of packets received from the user.
 For NAS usage, this AVP indicates how many packets have been received
 from the port over the course of a session being provided to a Framed
 User.  It can only be present in ACR messages with an Accounting-
 Record-Type of INTERIM_RECORD or STOP_RECORD.

8.4. Accounting-Output-Packets AVP

 The Accounting-Output-Packets (AVP Code 366) is of type Unsigned64
 and contains the number of IP packets sent to the user.
 For NAS usage, this AVP indicates how many packets have been sent to
 the port over the course of a session being provided to a Framed
 User.  It can only be present in ACR messages with an Accounting-
 Record-Type of INTERIM_RECORD or STOP_RECORD.

8.5. Acct-Session-Time AVP

 The Acct-Session-Time AVP (AVP Code 46) is of type Unsigned32 and
 indicates the length of the current session in seconds.  It can only
 be present in ACR messages with an Accounting-Record-Type of
 INTERIM_RECORD or STOP_RECORD.

8.6. Acct-Authentic AVP

 The Acct-Authentic AVP (AVP Code 45) is of type Enumerated and
 specifies how the user was authenticated.  The supported values are
 listed in [RADIUSTypes].  The following list is informational:

Calhoun, et al. Standards Track [Page 52] RFC 4005 Diameter Network Access Server Application August 2005

    1  RADIUS
    2  Local
    3  Remote
    4  Diameter

8.7. Accounting-Auth-Method AVP

 The Accounting-Auth-Method AVP (AVP Code 406) is of type Enumerated.
 A NAS MAY include this AVP in an Accounting-Request message to
 indicate the method used to authenticate the user.  (Note that this
 is equivalent to the RADIUS MS-Acct-Auth-Type VSA attribute).
 The following values are defined:
    1  PAP
    2  CHAP
    3  MS-CHAP-1
    4  MS-CHAP-2
    5  EAP
    7  None

8.8. Acct-Delay-Time

 The Acct-Delay-Time AVP (AVP Code 41) is of type Unsigned32 and
 indicates the number of seconds the Diameter client has been trying
 to send the Accounting-Request (ACR).  The accounting server may
 subtract this value from the time when the ACR arrives at the server
 to calculate the approximate time of the event that caused the ACR to
 be generated.
 This AVP is not used for retransmissions at the transport level (TCP
 or SCTP).  Rather, it may be used when an ACR command cannot be
 transmitted because there is no appropriate peer to transmit it to or
 was rejected because it could not be delivered.  In these cases, the
 command MAY be buffered and transmitted later, when an appropriate
 peer-connection is available or after sufficient time has passed that
 the destination-host may be reachable and operational.  If the ACR is
 resent in this way, the Acct-Delay-Time AVP SHOULD be included.  The
 value of this AVP indicates the number of seconds that elapsed
 between the time of the first attempt at transmission and the current
 attempt.

Calhoun, et al. Standards Track [Page 53] RFC 4005 Diameter Network Access Server Application August 2005

8.9. Acct-Link-Count

 The Acct-Link-Count AVP (AVP Code 51) is of type Unsigned32 and
 indicates the total number of links that have been active (current or
 closed) in a given multilink session at the time the accounting
 record is generated.  This AVP MAY be included in Accounting-Requests
 for any session that may be part of a multilink service.
 The Acct-Link-Count AVP may be used to make it easier for an
 accounting server to know when it has all the records for a given
 multilink service.  When the number of Accounting-Requests received
 with Accounting-Record-Type = STOP_RECORD and with the same Acct-
 Multi-Session-Id and unique Session-Ids equals the largest value of
 Acct-Link-Count seen in those Accounting-Requests, all STOP_RECORD
 Accounting-Requests for that multilink service have been received.
 The following example, showing eight Accounting-Requests, illustrates
 how the Acct-Link-Count AVP is used.  In the table below, only the
 relevant AVPs are shown, although additional AVPs containing
 accounting information will be present in the Accounting-Requests.
    Acct-Multi-                   Accounting-     Acct-
    Session-Id     Session-Id     Record-Type     Link-Count
    --------------------------------------------------------
      "...10"        "...10"      START_RECORD        1
      "...10"        "...11"      START_RECORD        2
      "...10"        "...11"      STOP_RECORD         2
      "...10"        "...12"      START_RECORD        3
      "...10"        "...13"      START_RECORD        4
      "...10"        "...12"      STOP_RECORD         4
      "...10"        "...13"      STOP_RECORD         4
      "...10"        "...10"      STOP_RECORD         4

8.10. Acct-Tunnel-Connection AVP

 The Acct-Tunnel-Connection AVP (AVP Code 68) is of type OctetString
 and contains the identifier assigned to the tunnel session.  This
 AVP, along with the Tunnel-Client-Endpoint and Tunnel-Server-Endpoint
 AVPs, may be used to provide a means to uniquely identify a tunnel
 session for auditing purposes.
 The format of the identifier in this AVP depends upon the value of
 the Tunnel-Type AVP.  For example, to identify an L2TP tunnel
 connection fully, the L2TP Tunnel Id and Call Id might be encoded in
 this field.  The exact encoding of this field is implementation
 dependent.

Calhoun, et al. Standards Track [Page 54] RFC 4005 Diameter Network Access Server Application August 2005

8.11. Acct-Tunnel-Packets-Lost AVP

 The Acct-Tunnel-Packets-Lost AVP (AVP Code 86) is of type Unsigned32
 and contains the number of packets lost on a given link.

9. RADIUS/Diameter Protocol Interactions

 This section describes some basic guidelines that servers acting as
 AAA Translation Agents may use.  A complete description of all the
 differences between RADIUS and Diameter is beyond the scope of this
 section and document.  Note that this document does not restrict
 implementations from creating additional translation methods, as long
 as the translation function doesn't violate the RADIUS or the
 Diameter protocols.
 Although the Diameter protocol is in many ways a superset of RADIUS
 functions, a number of RADIUS representations are not allowed, so
 that new capabilities can be used without the old problems.
 There are primarily two different situations that must be handled:
 one in which a RADIUS request is received that must be forwarded as a
 Diameter request, and another in which the inverse is true.  RADIUS
 does not support a peer-to-peer architecture, and server-initiated
 operations are generally not supported.  See [RADDynAuth] for an
 alternative.
 Some RADIUS attributes are encrypted.  RADIUS security and encryption
 techniques are applied on a hop-per-hop basis.  A Diameter agent will
 have to decrypt RADIUS attribute data entering the Diameter system,
 and if that information is forwarded, the agent MUST secure it by
 using Diameter specific techniques.
 Note that this section uses the two terms, "AVP" and "attribute", in
 a concise and specific manner.  The former is used to signify a
 Diameter AVP, and the latter to signify a RADIUS attribute.

9.1. RADIUS Request Forwarded as Diameter Request

 This section describes the actions that should be taken when a
 Translation Agent receives a RADIUS message to be translated to a
 Diameter message.
 Note that RADIUS servers are assumed to be stateless.  It is also
 quite possible for the RADIUS messages that comprise the session
 (i.e., authentication and accounting messages) to be handled by
 different Translation Agents in the proxy network.  Therefore, a
 RADIUS/Diameter Translation Agent SHOULD NOT be assumed to have an
 accurate track on session-state information.

Calhoun, et al. Standards Track [Page 55] RFC 4005 Diameter Network Access Server Application August 2005

 When a Translation Agent receives a RADIUS message, the following
 steps should be taken:
  1. If a Message-Authenticator attribute is present, the value MUST

be checked but not included in the Diameter message. If it is

       incorrect, the RADIUS message should be silently discarded.
       The gateway system SHOULD generate and include a Message-
       Authenticator in returned RADIUS responses.
  1. The transport address of the sender MUST be checked against the

NAS identifying attributes. See the description of NAS-

       Identifier and NAS-IP-Address below.
  1. The Translation Agent must maintain transaction state

information relevant to the RADIUS request, such as the

       Identifier field in the RADIUS header, any existing RADIUS
       Proxy-State attribute, and the source IP address and port
       number of the UDP packet.  These may be maintained locally in a
       state table or saved in a Proxy-Info AVP group.  A Diameter
       Session-Id AVP value must be created using a session state
       mapping mechanism.
  1. If the RADIUS request contained a State attribute and the

prefix of the data is "Diameter/", the data following the

       prefix contains the Diameter Origin-Host/Origin-Realm/Session-
       Id.  If no such attributes are present and the RADIUS command
       is an Access-Request, a new Session-Id is created.  The
       Session-Id is included in the Session-Id AVP.
  1. The Diameter Origin-Host and Origin-Realm AVPs MUST be created

and added by using the information from an FQDN corresponding

       to the NAS-IP-Address attribute (preferred if available),
       and/or to the NAS-Identifier attribute.  (Note that the RADIUS
       NAS-Identifier is not required to be an FQDN.)
  1. The response MUST have an Origin-AAA-Protocol AVP added,

indicating the protocol of origin of the message.

  1. The Proxy-Info group SHOULD be added, with the local server's

identity specified in the Proxy-Host AVP. This should ensure

       that the response is returned to this system.
  1. The Destination-Realm AVP is created from the information found

in the RADIUS User-Name attribute.

Calhoun, et al. Standards Track [Page 56] RFC 4005 Diameter Network Access Server Application August 2005

  1. If the RADIUS User-Password attribute is present, the password

must be unencrypted by using the link's RADIUS shared secret.

       The unencrypted value must be forwarded in a User-Password AVP
       using Diameter security.
  1. If the RADIUS CHAP-Password attribute is present, the Ident and

Data portion of the attribute are used to create the CHAP-Auth

       grouped AVP.
  1. If the RADIUS message contains an address attribute, it MUST be

converted to the appropriate Diameter AVP and type.

  1. If the RADIUS message contains Tunnel information [RADTunnels],

the attributes or tagged groups should each be converted to a

       Diameter Tunneling Grouped AVP set.  If the tunnel information
       contains a Tunnel-Password attribute, the RADIUS encryption
       must be resolved, and the password forwarded, by using Diameter
       security methods.
  1. If the RADIUS message received is an Accounting-Request, the

Acct-Status-Type attribute value must be converted to a

       Accounting-Record-Type AVP value.  If the Acct-Status-Type
       attribute value is STOP, the local server MUST issue a
       Session-Termination-Request message once the Diameter
       Accounting-Answer message has been received.
  1. If the Accounting message contains an Acct-Termination-Cause

attribute, it should be translated to the equivalent

       Termination-Cause AVP value.  (see below)
  1. If the RADIUS message contains the Accounting-Input-Octets,

Accounting-Input-Packets, Accounting-Output-Octets, or

       Accounting-Output-Packets, these attributes must be converted
       to the Diameter equivalents.  Further, if the Acct-Input-
       Gigawords or Acct-Output-Gigawords attributes are present,
       these must be used to properly compute the Diameter accounting
       AVPs.
 The corresponding Diameter response is always guaranteed to be
 received by the same Translation Agent that translated the original
 request, due to the contents of the Proxy-Info AVP group in the
 Diameter request.  The following steps are applied to the response
 message during the Diameter-to-RADIUS translation:
  1. If the Diameter Command-Code is set to AA-Answer and the

Result-Code AVP is set to DIAMETER_MULTI_ROUND_AUTH, the

       gateway must send a RADIUS Access-Challenge.  This must have
       the Origin-Host, Origin-Realm, and Diameter Session-Id AVPs

Calhoun, et al. Standards Track [Page 57] RFC 4005 Diameter Network Access Server Application August 2005

       encapsulated in the RADIUS State attribute, with the prefix
       "Diameter/", concatenated in the above order separated with "/"
       characters, in UTF-8 [UTF-8].  This is necessary to ensure that
       the Translation Agent receiving the subsequent RADIUS Access-
       Request will have access to the Session Identifier and be able
       to set the Destination-Host to the correct value.  If the
       Multi-Round-Time-Out AVP is present, the value of the AVP MUST
       be inserted in the RADIUS Session-Timeout AVP.
  1. If the Command-Code is set to AA-Answer, the Diameter Session-

Id AVP is saved in a new RADIUS Class attribute whose format

       consists of the string "Diameter/" followed by the Diameter
       Session Identifier.  This will ensure that the subsequent
       Accounting messages, which could be received by any Translation
       Agent, would have access to the original Diameter Session
       Identifier.
    -  If a Proxy-State attribute was present in the RADIUS request,
       the same attribute is added in the response.  This information
       may be found in the Proxy-Info AVP group, or in a local state
       table.
  1. If state information regarding the RADIUS request was saved in

a Proxy-Info AVP or local state table, the RADIUS Identifier

       and UDP IP Address and port number are extracted and used in
       issuing the RADIUS reply.
 When translating a Diameter AA-Answer (with successful result code)
 to RADIUS Access-Accept that contains a Session-Timeout or
 Authorization-Lifetime AVP, take the following steps:
  1. If the Diameter message contains a Session-Timeout AVP but no

Authorization-Lifetime AVP, translate it to a Session-Timeout

       attribute (not a Termination-Action).
  1. If the Diameter message contains an Authorization-Lifetime AVP

but no Session-Timeout AVP, translate it to a Session-Timeout

       attribute and a Termination-Action set to AA-REQUEST.  (Remove
       Authorization-Lifetime and Re-Auth-Request-Type.)
  1. If the Diameter message has both, the Session-Timeout must be

greater than or equal to the Authorization-Lifetime (required

       by [BASE]).  Translate it to a Session-Timeout value (with
       value from Authorization-Lifetime AVP, the smaller one) and
       with the Termination-Action set to AA-REQUEST.  (Remove the
       Authorization-Lifetime and Re-Auth-Request-Type.)

Calhoun, et al. Standards Track [Page 58] RFC 4005 Diameter Network Access Server Application August 2005

9.1.1. RADIUS Dynamic Authorization Considerations

 A Diameter/RADIUS gateway may communicate with a server that
 implements RADIUS Dynamic Authorization [RADDynAuth].  If the server
 supports these functions, it MUST be listening on the assigned port
 and would receive RADIUS CoA-Request and Disconnect-Request messages.
 These can be mapped into the Diameter Re-Auth-Request (RAR) and
 Abort-Session-Request (ASR) message exchanges, respectively [BASE].
 If the [RADDynAuth] is not supported, the port would not be active
 and the RADIUS server would receive an ICMP Port Unreachable
 indication.  Alternatively, if the messages are received but with an
 inappropriate Service-Type, the gateway can respond with the
 appropriate NAK message and an Error-Cause attribute with the value
 of 405, "Unsupported Service".
 The RADIUS CoA-Request and Disconnect-Request messages will not
 contain a Diameter Session-Id.  Diameter requires that this value
 match an active session context.  The gateway MUST have a session Id
 cache (or other means) to identify the sessions these functions
 pertain to.  If unable to identify the session, the gateway (or NAS)
 should return an Error-Cause value 503, "Session Context Not Found".
 The RADIUS CoA-Request message only supports a change of
 authorization attributes, and the received CoA-Request SHOULD include
 a Service-Type of "Authorize-Only".  This indicates an extended
 exchange request by the rules given in [RADDynAuth] section 3.2, note
 6.  This is the only type of exchange supported by Diameter [BASE].
 For the CoA-Request, the translated RAR message will have a Re-Auth-
 Type of AUTHORIZE_ONLY.  The returned RAA will be translated into a
 CoA-NAK with Error-Cause "Request Initiated".  The gateway's Diameter
 client SHOULD also start a reauthorization sequence by sending an AAR
 message, which will be translated into an Access-Request message.
 The RADIUS server will use the Access-Accept (or Access-Reject)
 message to convey the new authorization attributes, which the gateway
 will pass back in an AAA message.
 Any attributes included in the COA-Request or Access-Accept message
 are to be considered mandatory in Diameter.  If they cannot be
 supported, they MUST result in an error message return to the RADIUS
 server, with an Error-Cause of "Unsupported Attribute".  The Diameter
 NAS will attempt to apply all the attributes supplied in the AA
 message to the session.
 A RADIUS Disconnect-Request message received by the gateway would be
 translated to a Diameter Abort-Session-Request (ASR) message [BASE].
 The results will be returned by the Diameter client in an Abort-

Calhoun, et al. Standards Track [Page 59] RFC 4005 Diameter Network Access Server Application August 2005

 Session-Answer (ASA) message.  A success indication would translate
 to a RADIUS Disconnect-ACK, and a failure would generate a
 Disconnect-NAK.

9.2. Diameter Request Forwarded as RADIUS Request

 When a server receives a Diameter request to be forwarded to a RADIUS
 entity, the following are examples of the steps that may be taken:
  1. The Origin-Host AVP's value is inserted into the NAS-Identifier

attribute.

  1. The following information MUST be present in the corresponding

Diameter response and therefore MUST be saved, either in a

       local state table or encoded in a RADIUS Proxy-State attribute:
          1. Origin-Host AVP
          2. Session-Id AVP
          3. Proxy-Info AVP
          4. Any other AVP that MUST be present in the response and
             has no corresponding RADIUS attribute.
  1. If the CHAP-Auth AVP is present, the grouped AVPs are used to

create the RADIUS CHAP-Password attribute data.

  1. If the User-Password AVP is present, the data should be

encrypted and forwarded by using RADIUS rules. The same is

       true for any other RADIUS-encrypted attribute values.
  1. AVPs of the type Address must be translated to the

corresponding RADIUS attribute.

  1. If the Accounting-Input-Octets, Accounting-Input-Packets,

Accounting-Output-Octets, or Accounting-Output-Packets AVPs are

       present, they must be translated to the corresponding RADIUS
       attributes.  If the value of the Diameter AVPs do not fit
       within a 32-bit RADIUS attribute, the RADIUS Acct-Input-
       Gigawords and Acct-Output-Gigawords must be used.
  1. If the RADIUS link supports the Message-Authenticator attribute

[RADIUSExt], it SHOULD be generated and added to the request.

 When the corresponding response is received by the Translation Agent,
 which is guaranteed in the RADIUS protocol, the following steps may
 be taken:

Calhoun, et al. Standards Track [Page 60] RFC 4005 Diameter Network Access Server Application August 2005

  1. If the RADIUS code is set to Access-Challenge, a Diameter AA-

Answer message is created with the Result-Code set to

       DIAMETER_MULTI_ROUND_AUTH.  If the Session-Timeout AVP is
       present in the RADIUS message, its value is inserted into the
       Multi-Round-Time-Out AVP.
  1. If a Proxy-State attribute is present, extract the encoded

information; otherwise, retrieve the original Proxy-Info AVP

       group information from the local state table.
  1. The response's Origin-Host information is created from the FQDN

of the RADIUS message's source IP address. The same FQDN is

       also stored to a Route-Record AVP.
  1. The response's Destination-Host AVP is copied from the saved

request's Origin-Host information.

  1. The Session-Id information can be recovered from local state,

or from the constructed State or Proxy-State attribute, as

       above.
  1. If a Proxy-Info AVP was present in the request, the same AVP

MUST be added to the response.

  1. If the RADIUS State attributes are present, they must be

present in the Diameter response, minus those added by the

       gateway.
  1. Any other AVPs that were saved at request time, and that MUST

be present in the response, are added to the message.

 When translating a RADIUS Access-Accept to Diameter AA-Answer that
 contains a Session-Timeout attribute, do the following:
  1. If the RADIUS message contains a Session-Timeout attribute and

a Termination-Action attribute set to DEFAULT (or no

       Termination-Action attribute at all), translate it to AA-Answer
       with a Session-Timeout AVP and remove the Termination-Action
       attribute.
  1. If the RADIUS message contains a Session-Timeout attribute and

a Termination-Action attribute set to AA-REQUEST, translate it

       to AA-Answer with Authorization-Lifetime AVP and with Re-Auth-
       Request-Type set to AUTHORIZE_AUTHENTICATE and remove the
       Session-Timeout attribute.

Calhoun, et al. Standards Track [Page 61] RFC 4005 Diameter Network Access Server Application August 2005

9.2.1. RADIUS Dynamic Authorization Considerations

 A RADIUS/Diameter gateway communicating with a RADIUS client that
 implements RADIUS Dynamic Authorization [RADDynAuth] may translate
 Diameter Re-Auth-Request (RAR) messages and Abort-Session-Request
 (ASR) messages [BASE] into RADIUS CoA-Request and Disconnect-Request
 messages respectively.
 If the RADIUS client does not support the capability, the gateway
 will receive an ICMP Port Unreachable indication when it transmits
 the RADIUS message.  Even if the NAS supports [RADDynAuth], it may
 not support the Service-Type in the request message.  In this case it
 will respond with a NAK message and (optionally) an Error-Cause
 attribute with value 405, "Unsupported Service".  If the gateway
 encounters these error conditions, or if it does not support
 [RADDynAuth], it sends a Diameter Answer message with an Result-Code
 AVP of "DIAMETER_COMMAND_UNSUPPORTED" to the AAA server.
 When encoding the RADIUS messages, the gateway MUST include the
 Diameter Session-ID in the RADIUS State attribute value, as mentioned
 above.  The RADIUS client should return it in the response.
 A Diameter Re-Auth-Request (RAR) message [BASE] received by the
 gateway will be translated into a RADIUS CoA-Request and sent to the
 RADIUS client.  The RADIUS client should respond with a CoA-ACK or
 CoA-NAK message, which the gateway should translate into a Re-Auth-
 Answer (RAA) message.
 If the gateway receives a RADIUS CoA-NAK response containing a
 Service-Type Attribute with value "Authorize Only" and an Error-Cause
 Attribute with value "Request Initiated", this indicates an extended
 exchange request per [RADDynAuth] section 3.2, note 6.
 The response is translated to a Diameter Re-Auth-Answer (RAA) with a
 Result-Code AVP of "DIAMETER_LIMITED_SUCCESS" sent to the AAA server.
 Subsequently, the gateway should receive a RADIUS Access-Request from
 the NAS, with a Service-Type of "Authorize Only".  This is translated
 into a Diameter AA-Request with an Auth-Request-Type AVP of
 AUTHORIZE_ONLY and sent to the AAA server.  The AAA server will then
 reply with a Diameter AA-Answer, which is translated into a RADIUS
 Access-Accept or Access-Reject, depending on the value of the
 Result-Code AVP.
 A Diameter Abort-Session-Request (ASR) message [BASE] received by the
 gateway will be translated into a RADIUS Disconnect-Request and sent
 to the RADIUS client.  The RADIUS client should respond with a

Calhoun, et al. Standards Track [Page 62] RFC 4005 Diameter Network Access Server Application August 2005

 Disconnect-ACK or Disconnect-NAK message, which the gateway should
 translate into an Abort-Session-Answer (ASA) message.
 If the gateway receives a RADIUS Disconnect-NAK response containing a
 Service-Type Attribute with value "Authorize Only" and an Error-Cause
 Attribute with value "Request Initiated", the Disconnect-NAK response
 is translated into a Diameter Abort-Session-Answer (ASA) with a
 Result-Code AVP of "DIAMETER_LIMITED_SUCCESS" sent to the AAA server.
 Subsequently, the gateway should receive a RADIUS Access-Request from
 the NAS, with a Service-Type of "Authorize Only".  This is translated
 into a Diameter AA-Request with an Auth-Request-Type AVP of
 AUTHORIZE_ONLY and sent to the AAA server.  The AAA server will then
 reply with a Diameter AA-Answer, which is translated into a RADIUS
 Access-Accept or Access-Reject, depending on the value of the
 Result-Code AVP.

9.3. AVPs Used Only for Compatibility

 The AVPs defined in this section SHOULD only be used for backwards
 compatibility when a Diameter/RADIUS translation function is invoked
 and are not typically originated by Diameter systems during normal
 operations.
                                          +---------------------+
                                          |    AVP Flag rules   |
                                          |----+-----+----+-----|----+
                 AVP  Section             |    |     |SHLD| MUST|    |
 Attribute Name  Code Defined  Value Type |MUST| MAY | NOT|  NOT|Encr|
 -----------------------------------------|----+-----+----+-----|----|
 NAS-Identifier    32  9.3.1   UTF8String | M  |  P  |    |  V  | Y  |
 NAS-IP-Address     4  9.3.2   OctetString| M  |  P  |    |  V  | Y  |
 NAS-IPv6-Address  95  9.3.3   OctetString| M  |  P  |    |  V  | Y  |
 State             24  9.3.4   OctetString| M  |  P  |    |  V  | Y  |
 Termination-     295  9.3.5   Enumerated | M  |  P  |    |  V  | Y  |
    Cause                                 |    |     |    |     |    |
 Origin-AAA-      408  9.3.6   Enumerated | M  |  P  |    |  V  | Y  |
    Protocol                              |    |     |    |     |    |
 -----------------------------------------|----+-----+----+-----|----|

9.3.1. NAS-Identifier AVP

 The NAS-Identifier AVP (AVP Code 32) [RADIUS] is of type UTF8String
 and contains the identity of the NAS providing service to the user.
 This AVP SHOULD only be added by a RADIUS/Diameter Translation Agent.
 When this AVP is present, the Origin-Host AVP identifies the NAS
 providing service to the user.

Calhoun, et al. Standards Track [Page 63] RFC 4005 Diameter Network Access Server Application August 2005

 In RADIUS it would be possible for a rogue NAS to forge the NAS-
 Identifier attribute.  Diameter/RADIUS translation agents SHOULD
 attempt to check a received NAS-Identifier attribute against the
 source address of the RADIUS packet, by doing an A/AAAA RR query.  If
 the NAS-Identifier attribute contains an FQDN, then such a query
 would resolve to an IP address matching the source address.  However,
 the NAS-Identifier attribute is not required to contain an FQDN, so
 such a query could fail.  If it fails, an error should be logged, but
 no action should be taken, other than a reverse lookup on the source
 address and insert the resulting FQDN into the Route-Record AVP.
 Diameter agents and servers SHOULD check whether a NAS-Identifier AVP
 corresponds to an entry in the Route-Record AVP.  If no match is
 found, then an error is logged, but no other action is taken.

9.3.2. NAS-IP-Address AVP

 The NAS-IP-Address AVP (AVP Code 4) [RADIUS] is of type OctetString
 and contains the IP Address of the NAS providing service to the user.
 This AVP SHOULD only be added by a RADIUS/Diameter Translation Agent.
 When this AVP is present, the Origin-Host AVP identifies the NAS
 providing service to the user.
 In RADIUS it would be possible for a rogue NAS to forge the NAS-IP-
 Address attribute value.  Diameter/RADIUS translation agents MUST
 check a received NAS-IP-Address or NAS-IPv6-Address attribute against
 the source address of the RADIUS packet.  If they do not match and
 the Diameter/RADIUS translation agent does not know whether the
 packet was sent by a RADIUS proxy or NAS (e.g., no Proxy-State
 attribute), then by default it is assumed that the source address
 corresponds to a RADIUS proxy, and that the NAS Address is behind
 that proxy, potentially with some additional RADIUS proxies in
 between.  The Diameter/RADIUS translation agent MUST insert entries
 in the Route-Record AVP corresponding to the apparent route.  This
 implies doing a reverse lookup on the source address and NAS-IP-
 Address or NAS-IPv6-Address attributes to determine the corresponding
 FQDNs.
 If the source address and the NAS-IP-Address or NAS-IPv6-Address do
 not match, and the Diameter/RADIUS translation agent knows that it is
 talking directly to the NAS (e.g., there are no RADIUS proxies
 between it and the NAS), then the error should be logged, and the
 packet MUST be discarded.
 Diameter agents and servers MUST check whether the NAS-IP-Address AVP
 corresponds to an entry in the Route-Record AVP.  This is done by
 doing a reverse lookup (PTR RR) for the NAS-IP-Address to retrieve
 the corresponding FQDN, and by checking for a match with the Route-

Calhoun, et al. Standards Track [Page 64] RFC 4005 Diameter Network Access Server Application August 2005

 Record AVP.  If no match is found, then an error is logged, but no
 other action is taken.

9.3.3. NAS-IPv6-Address AVP

 The NAS-IPv6-Address AVP (AVP Code 95) [RADIUSIPv6] is of type
 OctetString and contains the IPv6 Address of the NAS providing
 service to the user.  This AVP SHOULD only be added by a
 RADIUS/Diameter Translation Agent.  When this AVP is present, the
 Origin-Host AVP identifies the NAS providing service to the user.
 In RADIUS it would be possible for a rogue NAS to forge the NAS-
 IPv6-Address attribute.  Diameter/RADIUS translation agents MUST
 check a received NAS-IPv6-Address attribute against the source
 address of the RADIUS packet.  If they do not match and the
 Diameter/RADIUS translation agent does not know whether the packet
 was sent by a RADIUS proxy or NAS (e.g., no Proxy-State attribute),
 then by default it is assumed that the source address corresponds to
 a RADIUS proxy, and that the NAS-IPv6-Address is behind that proxy,
 potentially with some additional RADIUS proxies in between.  The
 Diameter/RADIUS translation agent MUST insert entries in the Route-
 Record AVP corresponding to the apparent route.  This implies doing a
 reverse lookup on the source address and NAS-IPv6-Address attributes
 to determine the corresponding FQDNs.
 If the source address and the NAS-IPv6-Address do not match, and the
 Diameter/RADIUS translation agent knows that it is talking directly
 to the NAS (e.g., there are no RADIUS proxies between it and the
 NAS), then the error should be logged, and the packet MUST be
 discarded.
 Diameter agents and servers MUST check whether the NAS-IPv6-Address
 AVP corresponds to an entry in the Route-Record AVP.  This is done by
 doing a reverse lookup (PTR RR) for the NAS-IPv6-Address to retrieve
 the corresponding FQDN, and by checking for a match with the Record-
 Route AVP.  If no match is found, then an error is logged, but no
 other action is taken.

9.3.4. State AVP

 The State AVP (AVP Code 24) [RADIUS] is of type OctetString and has
 two uses in the Diameter NAS application.
 The State AVP MAY be sent by a Diameter Server to a NAS in an AA-
 Response command that contains a Result-Code of
 DIAMETER_MULTI_ROUND_AUTH.  If so, the NAS MUST return it unmodified
 in the subsequent AA-Request command.

Calhoun, et al. Standards Track [Page 65] RFC 4005 Diameter Network Access Server Application August 2005

 The State AVP MAY also be sent by a Diameter Server to a NAS in an
 AA-Response command that also includes a Termination-Action AVP with
 the value of AA-REQUEST.  If the NAS performs the Termination-Action
 by sending a new AA-Request command upon termination of the current
 service, it MUST return the State AVP unmodified in the new request
 command.
 In either usage, the NAS MUST NOT interpret the AVP locally.  Usage
 of the State AVP is implementation dependent.

9.3.5. Termination-Cause AVP Code Values

 This section defines a mapping between Termination-Cause AVP code
 values and RADIUS Acct-Terminate-Cause attribute code values from RFC
 2866 [RADIUSAcct] and [RADIUSTypes], thereby allowing a
 RADIUS/Diameter Translation Agent to convert between the attribute
 and AVP values.  This section thus extends the definitions in the
 "Termination-Cause AVP" section of the Base Diameter specification.

Calhoun, et al. Standards Track [Page 66] RFC 4005 Diameter Network Access Server Application August 2005

 The table in this section defines the mapping between Termination-
 Cause AVP and RADIUS Acct-Terminate-Cause causes.
                               +-----------------------+
                               |         Value         |
                               +-----------+-----------+
 Cause Value Name              |  RADIUS   | Diameter  |
 ------------------------------|-----------+-----------+
 User Request                  |     1     |   11      |
 Lost Carrier                  |     2     |   12      |
 Lost Service                  |     3     |   13      |
 Idle Timeout                  |     4     |   14      |
 Session Timeout               |     5     |   15      |
 Admin Reset                   |     6     |   16      |
 Admin Reboot                  |     7     |   17      |
 Port Error                    |     8     |   18      |
 NAS Error                     |     9     |   19      |
 NAS Request                   |     10    |   20      |
 NAS Reboot                    |     11    |   21      |
 Port Unneeded                 |     12    |   22      |
 Port Preempted                |     13    |   23      |
 Port Suspended                |     14    |   24      |
 Service Unavailable           |     15    |   25      |
 Callback                      |     16    |   26      |
 User Error                    |     17    |   27      |
 Host Request                  |     18    |   28      |
 Supplicant Restart            |     19    |   29      |  [RAD802.1X]
 Reauthentication Failure      |     20    |   30      |  [RAD802.1X]
 Port Reinit                   |     21    |   31      |  [RAD802.1X]
 Port Disabled                 |     22    |   32      |  [RAD802.1X]
 ------------------------------|-----------+-----------+
 From RFC 2866, the termination causes are as follows:
 User Request         User requested termination of service, for
                      example with LCP Terminate or by logging out.
 Lost Carrier         DCD was dropped on the port.
 Lost Service         Service can no longer be provided; for
                      example, user's connection to a host was
                      interrupted.
 Idle Timeout         Idle timer expired.
 Session Timeout      Maximum session length timer expired.
 Admin Reset          Administrator reset the port or session.

Calhoun, et al. Standards Track [Page 67] RFC 4005 Diameter Network Access Server Application August 2005

 Admin Reboot         Administrator is ending service on the NAS,
                      for example, prior to rebooting the NAS.
 Port Error           NAS detected an error on the port that
                      required ending the session.
 NAS Error            NAS detected an error (other than on the
                      port) that required ending the session.
 NAS Request          NAS ended the session for a non-error reason not
                      otherwise listed here.
 NAS Reboot           NAS ended the session to reboot
                      non-administratively ("crash").
 Port Unneeded        NAS ended the session because resource usage
                      fell below a low-water mark (for example, if
                      a bandwidth-on-demand algorithm decided that
                      the port was no longer needed).
 Port Preempted       NAS ended the session to allocate the
                      port to a higher priority use.
 Port Suspended       NAS ended the session to suspend a virtual
                      session.
 Service Unavailable  NAS was unable to provide requested service.
 Callback             NAS is terminating the current session
                      to perform callback for a new session.
 User Error           Input from user is in error, causing
                      session termination.
 Host Request         Login Host terminated session normally.

9.3.6. Origin-AAA-Protocol

 The Origin-AAA-Protocol AVP (AVP Code 408) is of the type Enumerated
 and should be inserted in a Diameter message translated by a gateway
 system from another AAA protocol, such as RADIUS.  It identifies the
 source protocol of the message to the Diameter system receiving the
 message.
 The supported values are:
       1       RADIUS

Calhoun, et al. Standards Track [Page 68] RFC 4005 Diameter Network Access Server Application August 2005

9.4. Prohibited RADIUS Attributes

 The following RADIUS attributes MUST NOT appear in a Diameter
 message.  Instead, they are translated to other Diameter AVPs or
 handled in some special manner.  The rules for the treatment of the
 attributes are discussed in sections 9.1, 9.2, and 9.6.
 Attribute Description       Defined     Nearest Diameter AVP
 -----------------------------------------------------------------
  3 CHAP-Password            RFC 2865    CHAP-Auth Group
 26 Vendor-Specific          RFC 2865    Vendor Specific AVP
 29 Termination-Action       RFC 2865    Authorization-Lifetime
 40 Acct-Status-Type         RFC 2866    Accounting-Record-Type
 42 Acct-Input-Octets        RFC 2866    Accounting-Input-Octets
 43 Acct-Output-Octets       RFC 2866    Accounting-Output-Octets
 47 Acct-Input-Packets       RFC 2866    Accounting-Input-Packets
 48 Acct-Output-Packets      RFC 2866    Accounting-Output-Packets
 49 Acct-Terminate-Cause     RFC 2866    Termination-Cause
 52 Acct-Input-Gigawords     RFC 2869    Accounting-Input-Octets
 53 Acct-Output-Gigawords    RFC 2869    Accounting-Output-Octets
 80 Message-Authenticator    RFC 2869    none - check and discard

9.5. Translatable Diameter AVPs

 In general, Diameter AVPs that are not RADIUS compatible have code
 values greater than 255.  The table in the section above shows the
 AVPs that can be converted into RADIUS attributes.
 Another problem may occur with Diameter AVP values that may be more
 than 253 octets in length.  Some RADIUS attributes (including but not
 limited to (8)Reply-Message, (79)EAP-Message, and (77)Connect-Info)
 allow concatenation of multiple instances to overcome this
 limitation.  If this is not possible, a Result-Code of
 DIAMETER_INVALID_AVP_LENGTH should be returned.

9.6. RADIUS Vendor Specific Attributes

 RADIUS supports the inclusion of Vendor Specific Attributes (VSAs)
 through the use of attribute 26.  The recommended format [RADIUS] of
 the attribute data field includes a 4 octet vendor code followed by a
 one octet vendor type field and a one octet length field.  The last
 two fields MAY be repeated.
 A system communicating between Diameter and RADIUS MAY have specific
 knowledge of vendor formats, and MAY be able to translate between the
 two formats.  However, given the deployment of many RADIUS vendor
 formats that do not follow the example format in RFC 2865 [RADIUS],
 (e.g., those that use a longer vendor type code) the translations in

Calhoun, et al. Standards Track [Page 69] RFC 4005 Diameter Network Access Server Application August 2005

 the next two sections will not work in general for those VSAs.  RFC
 2865 states that a robust implementation SHOULD support the field as
 undistinguished octets.
 Systems that don't have vendor format knowledge MAY discard such
 attributes without knowing a suitable translation.  An alternative
 format is under consideration [VSA], which proposes encodings that
 would preserve the native information and not require vendor
 knowledge in the gateway system.
 The following sections are an example for translating RADIUS VSAs
 that use the example RADIUS format, and Diameter VSAs that have type
 codes less than 255, and value field lengths less than 252.

9.6.1. Forwarding a Diameter Vendor Specific AVP as a RADIUS VSA

 For Type codes less than 255, the value field length MUST be less
 than 252 or the AVP will be discarded.  The RADIUS VSA attribute
 should consist of the following fields;
    RADIUS Type = 26, Vendor Specific Attribute
    RADIUS Length = total length of attribute (header + data)
    RADIUS Vendor code = Diameter Vendor code
    RADIUS Vendor type code = low order byte of Diameter AVP code
    RADIUS Vendor data length = length of Diameter data
 If the Diameter AVP code is greater than 255, then the RADIUS
 speaking code may use a Vendor specific field coding, if it knows one
 for that vendor.  Otherwise, the AVP will be ignored.  If it is
 flagged as Mandatory, a "DIAMETER_AVP_UNSUPPORTED" Result-Code will
 be returned, and the RADIUS message will not be sent.

9.6.2. Forwarding a RADIUS VSA as a Diameter Vendor Specific AVP

 The Diameter AVP will consist of the following fields:
    Diameter Flags: V=1, M=0, P=0
    Diameter Vendor code = RADIUS VSA Vendor code
    Diameter AVP code = RADIUS VSA Vendor type code
    Diameter AVP length = length of AVP (header + data)
    Diameter Data = RADIUS VSA vendor data
 Note that the VSAs are considered optional by RADIUS rules, and this
 specification does not set the Mandatory flag.  If an implementor
 desires a VSA be made mandatory because it represents a required
 service policy, the RADIUS gateway should have a process to set the
 bit on the Diameter side.

Calhoun, et al. Standards Track [Page 70] RFC 4005 Diameter Network Access Server Application August 2005

 If the RADIUS receiving code knows of vendor specific field
 interpretations for the specific vendor, it may employ them to parse
 an extended AVP code or data length.  Otherwise the recommended
 standard fields will be used.
 Nested Multiple vendor data fields MUST be expanded into multiple
 Diameter AVPs.

10. AVP Occurrence Tables

 The following tables present the AVPs used by NAS applications in NAS
 messages and specify in which Diameter messages they MAY or MAY NOT
 be present.  [BASE] messages and AVPs are not described in this
 document.  Note that AVPs that can only be present within a Grouped
 AVP are not represented in this table.
 The table uses the following symbols:
    0     The AVP MUST NOT be present in the message.
    0+    Zero or more instances of the AVP MAY be present in the
          message.
    0-1   Zero or one instance of the AVP MAY be present in the
          message.
    1     One instance of the AVP MUST be present in the message.

10.1. AA-Request/Answer AVP Table

 The table in this section is limited to the Command Codes defined in
 this specification.
                               +-----------+
                               |  Command  |
                               |-----+-----+
 Attribute Name                | AAR | AAA |
 ------------------------------|-----+-----+
 Acct-Interim-Interval         | 0   | 0-1 |
 ARAP-Challenge-Response       | 0   | 0-1 |
 ARAP-Features                 | 0   | 0-1 |
 ARAP-Password                 | 0-1 | 0   |
 ARAP-Security                 | 0-1 | 0-1 |
 ARAP-Security-Data            | 0+  | 0+  |
 ARAP-Zone-Access              | 0   | 0-1 |
 Auth-Application-Id           | 1   | 1   |
 Auth-Grace-Period             | 0-1 | 0-1 |
 Auth-Request-Type             | 1   | 1   |
 Auth-Session-State            | 0-1 | 0-1 |
 Authorization-Lifetime        | 0-1 | 0-1 |
 ------------------------------|-----+-----+

Calhoun, et al. Standards Track [Page 71] RFC 4005 Diameter Network Access Server Application August 2005

                               +-----------+
                               |  Command  |
                               |-----+-----+
 Attribute Name                | AAR | AAA |
 ------------------------------|-----+-----+
 Callback-Id                   | 0   | 0-1 |
 Callback-Number               | 0-1 | 0-1 |
 Called-Station-Id             | 0-1 | 0   |
 Calling-Station-Id            | 0-1 | 0   |
 CHAP-Auth                     | 0-1 | 0   |
 CHAP-Challenge                | 0-1 | 0   |
 Class                         | 0   | 0+  |
 Configuration-Token           | 0   | 0+  |
 Connect-Info                  | 0+  | 0   |
 Destination-Host              | 0-1 | 0   |
 Destination-Realm             | 1   | 0   |
 Error-Message                 | 0   | 0-1 |
 Error-Reporting-Host          | 0   | 0-1 |
 Failed-AVP                    | 0+  | 0+  |
 Filter-Id                     | 0   | 0+  |
 Framed-Appletalk-Link         | 0   | 0-1 |
 Framed-Appletalk-Network      | 0   | 0+  |
 Framed-Appletalk-Zone         | 0   | 0-1 |
 Framed-Compression            | 0+  | 0+  |
 Framed-Interface-Id           | 0-1 | 0-1 |
 Framed-IP-Address             | 0-1 | 0-1 |
 Framed-IP-Netmask             | 0-1 | 0-1 |
 Framed-IPv6-Prefix            | 0+  | 0+  |
 Framed-IPv6-Pool              | 0   | 0-1 |
 Framed-IPv6-Route             | 0   | 0+  |
 Framed-IPX-Network            | 0   | 0-1 |
 Framed-MTU                    | 0-1 | 0-1 |
 Framed-Pool                   | 0   | 0-1 |
 Framed-Protocol               | 0-1 | 0-1 |
 Framed-Route                  | 0   | 0+  |
 Framed-Routing                | 0   | 0-1 |
 Idle-Timeout                  | 0   | 0-1 |
 Login-IP-Host                 | 0+  | 0+  |
 Login-IPv6-Host               | 0+  | 0+  |
 Login-LAT-Group               | 0-1 | 0-1 |
 Login-LAT-Node                | 0-1 | 0-1 |
 Login-LAT-Port                | 0-1 | 0-1 |
 Login-LAT-Service             | 0-1 | 0-1 |
 Login-Service                 | 0   | 0-1 |
 Login-TCP-Port                | 0   | 0-1 |
 Multi-Round-Time-Out          | 0   | 0-1 |
 ------------------------------|-----+-----+

Calhoun, et al. Standards Track [Page 72] RFC 4005 Diameter Network Access Server Application August 2005

                               +-----------+
                               |  Command  |
                               |-----+-----+
 Attribute Name                | AAR | AAA |
 ------------------------------|-----+-----+
 NAS-Filter-Rule               | 0   | 0+  |
 NAS-Identifier                | 0-1 | 0   |
 NAS-IP-Address                | 0-1 | 0   |
 NAS-IPv6-Address              | 0-1 | 0   |
 NAS-Port                      | 0-1 | 0   |
 NAS-Port-Id                   | 0-1 | 0   |
 NAS-Port-Type                 | 0-1 | 0   |
 Origin-AAA-Protocol           | 0-1 | 0-1 |
 Origin-Host                   | 1   | 1   |
 Origin-Realm                  | 1   | 1   |
 Origin-State-Id               | 0-1 | 0-1 |
 Originating-Line-Info         | 0-1 | 0   |
 Password-Retry                | 0   | 0-1 |
 Port-Limit                    | 0-1 | 0-1 |
 Prompt                        | 0   | 0-1 |
 Proxy-Info                    | 0+  | 0+  |
 QoS-Filter-Rule               | 0   | 0+  |
 Re-Auth-Request-Type          | 0   | 0-1 |
 Redirect-Host                 | 0   | 0+  |
 Redirect-Host-Usage           | 0   | 0-1 |
 Redirect-Max-Cache-Time       | 0   | 0-1 |
 Reply-Message                 | 0   | 0+  |
 Result-Code                   | 0   | 1   |
 Route-Record                  | 0+  | 0+  |
 Service-Type                  | 0-1 | 0-1 |
 Session-Id                    | 1   | 1   |
 Session-Timeout               | 0   | 0-1 |
 State                         | 0-1 | 0-1 |
 Tunneling                     | 0+  | 0+  |
 User-Name                     | 0-1 | 0-1 |
 User-Password                 | 0-1 | 0   |
 ------------------------------|-----+-----+

10.2. Accounting AVP Tables

 The tables in this section are used to show which AVPs defined in
 this document are to be present and used in NAS application
 Accounting messages.  These AVPs are defined in this document, as
 well as in [BASE] and [RADIUSAcct].

Calhoun, et al. Standards Track [Page 73] RFC 4005 Diameter Network Access Server Application August 2005

10.2.1. Accounting Framed Access AVP Table

 The table in this section is used when the Service-Type specifies
 Framed Access.
                                        +-----------+
                                        |  Command  |
                                        |-----+-----+
 Attribute Name                         | ACR | ACA |
 ---------------------------------------|-----+-----+
 Accounting-Auth-Method                 | 0-1 | 0   |
 Accounting-Input-Octets                | 1   | 0   |
 Accounting-Input-Packets               | 1   | 0   |
 Accounting-Output-Octets               | 1   | 0   |
 Accounting-Output-Packets              | 1   | 0   |
 Accounting-Record-Number               | 0-1 | 0-1 |
 Accounting-Record-Type                 | 1   | 1   |
 Accounting-Realtime-Required           | 0-1 | 0-1 |
 Accounting-Sub-Session-Id              | 0-1 | 0-1 |
 Acct-Application-Id                    | 0-1 | 0-1 |
 Acct-Session-Id                        | 1   | 0-1 |
 Acct-Multi-Session-Id                  | 0-1 | 0-1 |
 Acct-Authentic                         | 1   | 0   |
 Acct-Delay-Time                        | 0-1 | 0   |
 Acct-Interim-Interval                  | 0-1 | 0-1 |
 Acct-Link-Count                        | 0-1 | 0   |
 Acct-Session-Time                      | 1   | 0   |
 Acct-Tunnel-Connection                 | 0-1 | 0   |
 Acct-Tunnel-Packets-Lost               | 0-1 | 0   |
 Authorization-Lifetime                 | 0-1 | 0   |
 Callback-Id                            | 0-1 | 0   |
 Callback-Number                        | 0-1 | 0   |
 Called-Station-Id                      | 0-1 | 0   |
 Calling-Station-Id                     | 0-1 | 0   |
 Class                                  | 0+  | 0+  |
 Connection-Info                        | 0+  | 0   |
 Destination-Host                       | 0-1 | 0   |
 Destination-Realm                      | 1   | 0   |
 Event-Timestamp                        | 0-1 | 0-1 |
 Error-Message                          | 0   | 0-1 |
 Error-Reporting-Host                   | 0   | 0-1 |
 Failed-AVP                             | 0   | 0+  |
 ---------------------------------------|-----+-----+

Calhoun, et al. Standards Track [Page 74] RFC 4005 Diameter Network Access Server Application August 2005

                                        +-----------+
                                        |  Command  |
                                        |-----+-----+
 Attribute Name                         | ACR | ACA |
 ---------------------------------------|-----+-----+
 Framed-AppleTalk-Link                  | 0-1 | 0   |
 Framed-AppleTalk-Network               | 0-1 | 0   |
 Framed-AppleTalk-Zone                  | 0-1 | 0   |
 Framed-Compression                     | 0-1 | 0   |
 Framed-IP-Address                      | 0-1 | 0   |
 Framed-IP-Netmask                      | 0-1 | 0   |
 Framed-IPv6-Prefix                     | 0+  | 0   |
 Framed-IPv6-Pool                       | 0-1 | 0   |
 Framed-IPX-Network                     | 0-1 | 0   |
 Framed-MTU                             | 0-1 | 0   |
 Framed-Pool                            | 0-1 | 0   |
 Framed-Protocol                        | 0-1 | 0   |
 Framed-Route                           | 0-1 | 0   |
 Framed-Routing                         | 0-1 | 0   |
 NAS-Filter-Rule                        | 0+  | 0   |
 NAS-Identifier                         | 0-1 | 0-1 |
 NAS-IP-Address                         | 0-1 | 0-1 |
 NAS-IPv6-Address                       | 0-1 | 0-1 |
 NAS-Port                               | 0-1 | 0-1 |
 NAS-Port-Id                            | 0-1 | 0-1 |
 NAS-Port-Type                          | 0-1 | 0-1 |
 Origin-AAA-Protocol                    | 0-1 | 0-1 |
 Origin-Host                            | 1   | 1   |
 Origin-Realm                           | 1   | 1   |
 Origin-State-Id                        | 0-1 | 0-1 |
 Originating-Line-Info                  | 0-1 | 0   |
 Proxy-Info                             | 0+  | 0+  |
 QoS-Filter-Rule                        | 0+  | 0   |
 Route-Record                           | 0+  | 0+  |
 Result-Code                            | 0   | 1   |
 Service-Type                           | 0-1 | 0-1 |
 Session-Id                             | 1   | 1   |
 Termination-Cause                      | 0-1 | 0-1 |
 Tunnel-Assignment-Id                   | 0-1 | 0   |
 Tunnel-Client-Endpoint                 | 0-1 | 0   |
 Tunnel-Medium-Type                     | 0-1 | 0   |
 Tunnel-Private-Group-Id                | 0-1 | 0   |
 Tunnel-Server-Endpoint                 | 0-1 | 0   |
 Tunnel-Type                            | 0-1 | 0   |
 User-Name                              | 0-1 | 0-1 |
 Vendor-Specific-Application-Id         | 0-1 | 0-1 |
 ---------------------------------------|-----+-----+

Calhoun, et al. Standards Track [Page 75] RFC 4005 Diameter Network Access Server Application August 2005

10.2.2. Accounting Non-Framed Access AVP Table

 The table in this section is used when the Service-Type specifies
 Non-Framed Access.
                                        +-----------+
                                        |  Command  |
                                        |-----+-----+
 Attribute Name                         | ACR | ACA |
 ---------------------------------------|-----+-----+
 Accounting-Auth-Method                 | 0-1 | 0   |
 Accounting-Input-Octets                | 1   | 0   |
 Accounting-Output-Octets               | 1   | 0   |
 Accounting-Record-Type                 | 1   | 1   |
 Accounting-Record-Number               | 0-1 | 0-1 |
 Accounting-Realtime-Required           | 0-1 | 0-1 |
 Accounting-Sub-Session-Id              | 0-1 | 0-1 |
 Acct-Application-Id                    | 0-1 | 0-1 |
 Acct-Session-Id                        | 1   | 0-1 |
 Acct-Multi-Session-Id                  | 0-1 | 0-1 |
 Acct-Authentic                         | 1   | 0   |
 Acct-Delay-Time                        | 0-1 | 0   |
 Acct-Interim-Interval                  | 0-1 | 0-1 |
 Acct-Link-Count                        | 0-1 | 0   |
 Acct-Session-Time                      | 1   | 0   |
 Authorization-Lifetime                 | 0-1 | 0   |
 Callback-Id                            | 0-1 | 0   |
 Callback-Number                        | 0-1 | 0   |
 Called-Station-Id                      | 0-1 | 0   |
 Calling-Station-Id                     | 0-1 | 0   |
 Class                                  | 0+  | 0+  |
 Connection-Info                        | 0+  | 0   |
 Destination-Host                       | 0-1 | 0   |
 Destination-Realm                      | 1   | 0   |
 Event-Timestamp                        | 0-1 | 0-1 |
 Error-Message                          | 0   | 0-1 |
 Error-Reporting-Host                   | 0   | 0-1 |
 Failed-AVP                             | 0   | 0+  |
 Login-IP-Host                          | 0+  | 0   |
 Login-IPv6-Host                        | 0+  | 0   |
 Login-LAT-Service                      | 0-1 | 0   |
 Login-LAT-Node                         | 0-1 | 0   |
 Login-LAT-Group                        | 0-1 | 0   |
 Login-LAT-Port                         | 0-1 | 0   |
 Login-Service                          | 0-1 | 0   |
 Login-TCP-Port                         | 0-1 | 0   |
 ---------------------------------------|-----+-----+

Calhoun, et al. Standards Track [Page 76] RFC 4005 Diameter Network Access Server Application August 2005

                                        +-----------+
                                        |  Command  |
                                        |-----+-----+
 Attribute Name                         | ACR | ACA |
 ---------------------------------------|-----+-----+
 NAS-Identifier                         | 0-1 | 0-1 |
 NAS-IP-Address                         | 0-1 | 0-1 |
 NAS-IPv6-Address                       | 0-1 | 0-1 |
 NAS-Port                               | 0-1 | 0-1 |
 NAS-Port-Id                            | 0-1 | 0-1 |
 NAS-Port-Type                          | 0-1 | 0-1 |
 Origin-AAA-Protocol                    | 0-1 | 0-1 |
 Origin-Host                            | 1   | 1   |
 Origin-Realm                           | 1   | 1   |
 Origin-State-Id                        | 0-1 | 0-1 |
 Originating-Line-Info                  | 0-1 | 0   |
 Proxy-Info                             | 0+  | 0+  |
 QoS-Filter-Rule                        | 0+  | 0   |
 Route-Record                           | 0+  | 0+  |
 Result-Code                            | 0   | 1   |
 Session-Id                             | 1   | 1   |
 Service-Type                           | 0-1 | 0-1 |
 Termination-Cause                      | 0-1 | 0-1 |
 User-Name                              | 0-1 | 0-1 |
 Vendor-Specific-Application-Id         | 0-1 | 0-1 |
 ---------------------------------------|-----+-----+

11. IANA Considerations

 This section provides guidance to the Internet Assigned Numbers
 Authority (IANA) regarding registration of values related to the
 Diameter protocol, in accordance with BCP 26 [IANAConsid].
 This document defines values in the namespaces that have been created
 and defined in the Diameter Base [BASE].  The IANA Considerations
 section of that document details the assignment criteria.  Values
 assigned in this document, or by future IANA action, must be
 coordinated within this shared namespace.

11.1. Command Codes

 This specification assigns the value 265 from the Command Code
 namespace defined in [BASE].  See sections 3.1 and 3.2 for the
 assignment of the namespace in this specification.

Calhoun, et al. Standards Track [Page 77] RFC 4005 Diameter Network Access Server Application August 2005

11.2. AVP Codes

 This specification assigns the values 363 - 366 and 400 - 408 from
 the AVP Code namespace defined in [BASE].  See sections 4 and 5 for
 the assignment of the namespace in this specification.  Note that the
 values 363 - 366 are jointly, but consistently, assigned in
 [DiamMIP].  This document also creates one new namespace to be
 managed by IANA, as described in section 11.5.
 This specification also specifies the use of AVPs in the 0 - 255
 range, which are defined in [RADIUSTypes].  These values are assigned
 by the policy in RFC 2865 section 6 [RADIUS] and are amended by RFC
 3575 [RADIUSIANA].

11.3. Application Identifier

 This specification uses the value one (1) in the Application
 Identifier namespace as assigned in [BASE].  See section 1.2 above
 for more information.

11.4. CHAP-Algorithm AVP Values

 As defined in section 5.5, the CHAP-Algorithm AVP (AVP Code 403) uses
 the values of the "PPP AUTHENTICATION ALGORITHMS" namespace defined
 in [PPPCHAP].

11.5. Accounting-Auth-Method AVP Values

 As defined in section 8.6, the Accounting-Auth-Method AVP (AVP Code
 406) defines the values 1 - 5.  All remaining values are available
 for assignment via IETF Consensus [IANA].

11.6. Origin-AAA-Protocol AVP Values

 As defined in section 9.3.6, the Origin-AAA-Protocol AVP (AVP Code
 408) defines the value 1. All remaining values are available for
 assignment with a "Specification Required" policy [IANAConsid].

12. Security Considerations

 This document describes the extension of Diameter for the NAS
 application.  The security considerations of the Diameter protocol
 itself have been discussed in [BASE].  Use of this application of
 Diameter MUST take into consideration the security issues and
 requirements of the Base protocol.

Calhoun, et al. Standards Track [Page 78] RFC 4005 Diameter Network Access Server Application August 2005

 This document does not contain a security protocol but does discuss
 how PPP authentication protocols can be carried within the Diameter
 protocol.  The PPP authentication protocols described are PAP and
 CHAP.
 The use of PAP SHOULD be discouraged, as it exposes users' passwords
 to possibly non-trusted entities.  However, PAP is also frequently
 used for use with One-Time Passwords, which do not expose a security
 risk.
 This document also describes how CHAP can be carried within the
 Diameter protocol, which is required for RADIUS backward
 compatibility.  The CHAP protocol, as used in a RADIUS environment,
 facilitates authentication replay attacks.
 The use of the EAP authentication protocols described in [DiamEAP]
 can offer better security, given a method suitable for the
 circumstances.

13. References

13.1. Normative References

 [BASE]         Calhoun, P., Loughney, J., Guttman, E., Zorn, G., and
                J. Arkko, "Diameter Base Protocol", RFC 3588,
                September 2003.
 [DiamTrans]    Aboba, B. and J. Wood, "Authentication, Authorization
                and Accounting (AAA) Transport Profile", RFC 3539,
                June 2003.
 [RADIUS]       Rigney, C., Willens, S., Rubens, A., and W. Simpson,
                "Remote Authentication Dial In User Service (RADIUS)",
                RFC 2865, June 2000.
 [RADIUSTypes]  IANA, "RADIUS Types", URL:
                <http://www.iana.org/assignments/radius-types>
 [RADIUSIPv6]   Aboba, B., Zorn, G., and D. Mitton, "RADIUS and IPv6",
                RFC 3162, August 2001.
 [IPv6Addr]     Nerenberg, L., "IMAP4 Binary Content Extension", RFC
                3516, April 2003.
 [PPPCHAP]      Simpson, W., "PPP Challenge Handshake Authentication
                Protocol (CHAP)", RFC 1994, August 1996.

Calhoun, et al. Standards Track [Page 79] RFC 4005 Diameter Network Access Server Application August 2005

 [IANAConsid]   Narten, T. and H. Alvestrand, "Guidelines for Writing
                an IANA Considerations Section in RFCs", BCP 26, RFC
                2434, October 1998.
 [IANA]         IANA Assigned Numbers Database, URL:
                <http://www.iana.org/numbers.html>
 [Keywords]     Bradner, S., "Key words for use in RFCs to Indicate
                Requirement Levels", BCP 14, RFC 2119, March 1997.
 [ANITypes]     NANPA Number Resource Info, ANI Assignments, URL:
                <http://www.nanpa.com/number_resource_info/
                ani_ii_assignments.html>

13.2. Informative References

 [RADIUSAcct]   Rigney, C., "RADIUS Accounting", RFC 2866, June 2000.
 [RADIUSExt]    Rigney, C., Willats, W., and P. Calhoun, "RADIUS
                Extensions", RFC 2869, June 2000.
 [RADTunnels]   Zorn, G., Leifer, D., Rubens, A., Shriver, J.,
                Holdrege, M., and I. Goyret, "RADIUS Attributes for
                Tunnel Protocol Support", RFC 2868, June 2000.
 [RADTunlAcct]  Zorn, G., Aboba, B., and D. Mitton, "RADIUS Accounting
                Modifications for Tunnel Protocol Support", RFC 2867,
                June 2000.
 [RADDynAuth]   Chiba, M., Dommety, G., Eklund, M., Mitton, D., and B.
                Aboba, "Dynamic Authorization Extensions to Remote
                Authentication Dial In User Service (RADIUS)", RFC
                3576, July 2003.
 [RADIUSIANA]   Aboba, B., "IANA Considerations for RADIUS (Remote
                Authentication Dial In User Service)", RFC 3575, July
                2003.
 [NASModel]     Mitton, D. and M. Beadles, "Network Access Server
                Requirements Next Generation (NASREQNG) NAS Model",
                RFC 2881, July 2000.
 [NASCriteria]  Beadles, M. and D. Mitton, "Criteria for Evaluating
                Network Access Server Protocols", RFC 3169, September
                2001.

Calhoun, et al. Standards Track [Page 80] RFC 4005 Diameter Network Access Server Application August 2005

 [AAACriteria]  Aboba, B., Calhoun, P., Glass, S., Hiller, T., McCann,
                P., Shiino, H., Zorn, G., Dommety, G., Perkins, C.,
                Patil, B., Mitton, D., Manning, S., Beadles, M.,
                Walsh, P., Chen, X., Sivalingham, S., Hameed, A.,
                Munson, M., Jacobs, S., Lim, B., Hirschman, B., Hsu,
                R., Xu, Y., Campbell, E., Baba, S., and E. Jaques,
                "Criteria for Evaluating AAA Protocols for Network
                Access", RFC 2989, November 2000.
 [DiamEAP]      Eronen, P., "Diameter EAP Application", Work in
                Progress, May 2004.
 [DiamCMS]      Calhoun, P., Bulley, W., and S. Farrell, "Diameter CMS
                Security Application", Work in Progress, March 2002.
 [DiamMIP]      Calhoun, P., Johansson, T., Perkins, C., Hiller, T.,
                and P. McCann "Diameter Mobile IPv4 Application", RFC
                4004, August 2005.
 [VSA]          Mitton, D., "Diameter/RADIUS Vendor Specific AVP
                Translation", Work in Progress, April 2005.
 [RAD802.1X]    Congdon, P., Aboba, B., Smith, A., Zorn, G., and J.
                Roese, "IEEE 802.1X Remote Authentication Dial In User
                Service (RADIUS) Usage Guidelines", RFC 3580,
                September 2003.
 [CDMA2000]     3GPP2 "P.S0001-B", Wireless IP Network Standard,
                October 2002.
                http://www.3gpp2.com/Public_html/specs/P.S0001-
                B_v1.0.pdf
 [AppleTalk]    Sidhu, Gursharan; Andrews, Richard F. & Oppenheimer,
                Alan B.  "Inside AppleTalk", Second Edition, Apple
                Computer., 1990
 [ARAP]         Apple Remote Access Protocol (ARAP) Version 2.0
                External Reference Specification", Apple Computer,
                September 1994, R0612LL/B
 [IPX]          Novell, Inc., "NetWare System Technical Interface
                Overview", June 1989,  # 883-000780-001
 [LAT]          Local Area Transport (LAT) Specification V5.0, Digital
                Equipment Corp., AA-NL26A-TE, June 1989

Calhoun, et al. Standards Track [Page 81] RFC 4005 Diameter Network Access Server Application August 2005

 [DIFFSERV]     Nichols, K., Blake, S., Baker, F., and D. Black,
                "Definition of the Differentiated Services Field (DS
                Field) in the IPv4 and IPv6 Headers", RFC 2474,
                December 1998.
 [DIFFSERVAF]   Heinanen, J., Baker, F., Weiss, W., and J. Wroclawski,
                "Assured Forwarding PHB Group", RFC 2597, June 1999.
 [DIFFSERVEF]   Davie, B., Charny, A., Bennet, J.C., Benson, K., Le
                Boudec, J., Courtney, W., Davari, S., Firoiu, V., and
                D. Stiliadis, "An Expedited Forwarding PHB (Per-Hop
                Behavior)", RFC 3246, March 2002.
 [UTF-8]        Yergeau, F., "UTF-8, a transformation format of ISO
                10646", STD 63, RFC 3629, November 2003.
 [ISOLatin]     ISO 8859. International Standard -- Information
                Processing -- 8-bit Single-Byte Coded Graphic
                Character Sets -- Part 1: Latin Alphabet No. 1, ISO
                8859-1:1987.  URL:
                <http://www.iso.ch/cate/d16338.html>
 [PPP]          Simpson, W., "The Point-to-Point Protocol (PPP)", STD
                51, RFC 1661, July 1994.
 [PAP]          Lloyd, B. and W. Simpson, "PPP Authentication
                Protocols", RFC 1334, October 1992.
 [L2TP]         Townsley, W., Valencia, A., Rubens, A., Pall, G.,
                Zorn, G., and B. Palter, "Layer Two Tunneling Protocol
                "L2TP"", RFC 2661, August 1999.
 [PPPMP]        Sklower, K., Lloyd, B., McGregor, G., Carr, D., and T.
                Coradetti, "The PPP Multilink Protocol (MP)", RFC
                1990, August 1996.
 [PPTP]         Hamzeh, K., Pall, G., Verthein, W., Taarud, J.,
                Little, W., and G. Zorn, "Point-to-Point Tunneling
                Protocol", RFC 2637, July 1999.
 [IEEE 802.11F] IEEE, "Trial-Use Recommended Practice for Multi-Vendor
                Access Point Interoperability via an Inter-Access
                Point Protocol Across Distribution Systems Supporting
                IEEE 802.11 Operation", IEEE 802.11F-2003, June 2003.

Calhoun, et al. Standards Track [Page 82] RFC 4005 Diameter Network Access Server Application August 2005

14. Acknowledgements

 The authors would like to thank Carl Rigney, Allan C. Rubens, William
 Allen Simpson, and Steve Willens for their work on the original
 RADIUS [RADIUS], from which many of the concepts in this
 specification were derived.  Thanks, also, to Carl Rigney for
 [RADIUSAcct] and [RADIUSExt]; Ward Willats for [RADIUSExt]; Glen
 Zorn, Bernard Aboba, and Dave Mitton for [RADTunlAcct] and
 [RADIUSIPv6]; and Dory Leifer, John Shriver, Matt Holdrege, and
 Ignacio Goyret for their work on [RADTunnels].  This document stole
 text and concepts from both [RADTunnels] and [RADIUSExt].  Thanks go
 to Carl Williams for providing IPv6-specific text.
 The authors would also like to acknowledge the following people for
 their contributions in the development of the Diameter protocol:
 Bernard Aboba, Jari Arkko, William Bulley, Kuntal Chowdhury, Daniel
 C. Fox, Lol Grant, Nancy Greene, Jeff Hagg, Peter Heitman, Paul
 Krumviede, Fergal Ladley, Ryan Moats, Victor Muslin, Kenneth Peirce,
 Sumit Vakil, John R. Vollbrecht, and Jeff Weisberg.
 Finally, Pat Calhoun would like to thank Sun Microsystems, as most of
 the effort put into this document was done while he was in their
 employ.

Calhoun, et al. Standards Track [Page 83] RFC 4005 Diameter Network Access Server Application August 2005

Authors' Addresses

 Pat Calhoun
 Cisco Systems, Inc.
 170 West Tasman Drive
 San Jose, CA 95134
 USA
 Phone: +1 408-853-5269
 EMail: pcalhoun@cisco.com
 Glen Zorn
 Cisco Systems, Inc.
 500 108th Avenue N.E., Suite 500
 Bellevue, WA 98004
 USA
 Phone:  1 425-471-4861
 EMail: gwz@cisco.com
 David Spence
 3259 Bluett Rd.
 Ann Arbor, MI  48105
 USA
 Phone: +1 734 834 6481
 EMail: dspence@computer.org
 David Mitton
 Circular Networks
 733 Turnpike St #154
 North Andover, MA 01845
 EMail: dmitton@circularnetworks.com

Calhoun, et al. Standards Track [Page 84] RFC 4005 Diameter Network Access Server Application August 2005

Full Copyright Statement

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 contained in BCP 78, and except as set forth therein, the authors
 retain all their rights.
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Acknowledgement

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Calhoun, et al. Standards Track [Page 85]

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