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rfc:rfc6005

Internet Engineering Task Force (IETF) L. Berger Request for Comments: 6005 LabN Category: Standards Track D. Fedyk ISSN: 2070-1721 Alcatel-Lucent

                                                          October 2010
     Generalized MPLS (GMPLS) Support for Metro Ethernet Forum
              and G.8011 User Network Interface (UNI)

Abstract

 This document describes a method for controlling two specific types
 of Ethernet switching via a GMPLS-based User Network Interface (UNI).
 This document supports the types of switching required by the
 Ethernet services that have been defined in the context of the Metro
 Ethernet Forum (MEF) and International Telecommunication Union (ITU)
 G.8011.  This document is the UNI companion to "Generalized MPLS
 (GMPLS) Support for Metro Ethernet Forum and G.8011 Ethernet Service
 Switching".  This document does not define or limit the underlying
 intra-domain or Internal NNI (I-NNI) technology used to support the
 UNI.

Status of This Memo

 This is an Internet Standards Track document.
 This document is a product of the Internet Engineering Task Force
 (IETF).  It represents the consensus of the IETF community.  It has
 received public review and has been approved for publication by the
 Internet Engineering Steering Group (IESG).  Further information on
 Internet Standards is available in Section 2 of RFC 5741.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 http://www.rfc-editor.org/info/rfc6005.

Berger & Fedyk Standards Track [Page 1] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

Copyright Notice

 Copyright (c) 2010 IETF Trust and the persons identified as the
 document authors.  All rights reserved.
 This document is subject to BCP 78 and the IETF Trust's Legal
 Provisions Relating to IETF Documents
 (http://trustee.ietf.org/license-info) in effect on the date of
 publication of this document.  Please review these documents
 carefully, as they describe your rights and restrictions with respect
 to this document.  Code Components extracted from this document must
 include Simplified BSD License text as described in Section 4.e of
 the Trust Legal Provisions and are provided without warranty as
 described in the Simplified BSD License.

Table of Contents

 1. Introduction ....................................................3
    1.1. Overview ...................................................4
    1.2. Conventions Used in This Document ..........................5
 2. Common Signaling Support ........................................5
    2.1. UNI Addressing .............................................5
    2.2. Ethernet Endpoint (UNI) Identification .....................6
         2.2.1. Address Resolution ..................................6
    2.3. Connection Identification ..................................7
 3. EPL Service .....................................................7
 4. EVPL Service ....................................................7
    4.1. Egress VLAN ID Control and VLAN ID Preservation ............7
 5. IANA Considerations .............................................8
    5.1. Error Value: Routing Problem/Unknown Endpoint ..............8
 6. Security Considerations .........................................8
 7. References ......................................................8
    7.1. Normative References .......................................8
    7.2. Informative References .....................................9
 Acknowledgments ....................................................9

Berger & Fedyk Standards Track [Page 2] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

1. Introduction

 [MEF6] and [G.8011] provide parallel frameworks for defining network-
 oriented characteristics of Ethernet services in transport networks.
 The framework discusses general Ethernet connection characteristics,
 Ethernet User Network Interfaces (UNIs), and Ethernet Network-Network
 Interfaces (NNIs).  Within this framework, [G.8011.1] defines the
 Ethernet Private Line (EPL) service and [G.8011.2] defines the
 Ethernet Virtual Private Line (EVPL) service. [MEF6] covers both
 service types.  [MEF10.1] defines service parameters and [MEF11]
 provides UNI requirements and framework.
 This document provides a method for GMPLS-based control of Label
 Switched Paths (LSPs) that support the transport services defined in
 the above documents at the UNI network reference points.  This
 document does not define or limit the underlying intra-domain or
 Internal NNI (I-NNI) technology used to support the UNI.  This
 document makes use of the GMPLS extensions defined in [RFC6004] and
 [RFC6002].
 The scope of this document covers Ethernet UNI applications, and it
 is intended to be consistent with the GMPLS overlay model presented
 in [RFC4208] and aligned with GMPLS Core Network signaling.  The
 scope and reference model used in this document are represented in
 Figure 1, which is based on Figure 1 of [RFC4208].
 Figure 1 shows two core networks, each containing two core nodes.
 The core nodes are labeled 'CN'.  Connected to each CN is an edge
 node.  The edge nodes are labeled 'EN'.  Each EN supports Ethernet
 Networks and use Ethernet services provided by the core nodes via a
 UNI.  Two services are represented: one EPL and one EVPL type
 service.  Signaling within the core network is out of scope of this
 document and may include any technology that supports overlay UNI
 services.  The UNI function in the edge node can be referred to as
 the UNI client, or UNI-C, and in the CN as UNI network, or UNI-N.

Berger & Fedyk Standards Track [Page 3] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

      Ethernet                                          Ethernet
      Network       +----------+    +-----------+       Network
    +---------+     |          |    |           |     +---------+
    |  +----+ |     |  +-----+ |    |  +-----+  |     | +----+  |
 ------+    | | EPL |  |     | |    |  |     |  | EPL | |    +------
 ------+ EN +-+-----+--+ CN  +---------+  CN +--+-----+-+ EN +------
    |  |    | |  +--+--|     +---+  |  |     +--+-----+-+    |  |
    |  +----+ |  |  |  +--+--+ | |  |  +--+--+  |     | +----+  |
    |         |  |  |     |    | |  |     |     |     |         |
    +---------+  |  |     |    | |  |     |     |     +---------+
                 |  |     |    | |  |     |     |
    +---------+  |  |     |    | |  |     |     |     +---------+
    |         |  |  |  +--+--+ | |  |  +--+--+  |     |         |
    |  +----+ |  |  |  |     | | +-----+     |  |     | +----+  |
 ------+    +-+--+  |  | CN  +---------+ CN  |  |     | |    +------
 ------+ EN +-+-----+--+     | |    |  |     +--+-----+-+ EN +------
    |  |    | |EVPL |  +-----+ |    |  +-----+  |EVPL | |    |  |
    |  +----+ |     |          |    |           |     | +----+  |
    |         |     +----------+    |-----------+     |         |
    +---------+            Core Network(s)            +---------+
      Ethernet  UNI                               UNI   Ethernet
      Network <----->                           <-----> Network
                        Scope of This Document
                      Legend:   EN  -  Edge Node
                                CN  -  Core Node
                Figure 1: Ethernet UNI Reference Model

1.1. Overview

 This document uses a common approach to supporting the switching
 implied by the Ethernet services defined in [MEF6], [G.8011.1], and
 [G.8011.2].  The approach builds on standard GMPLS mechanisms to
 deliver the required control capabilities.  This document reuses the
 GMPLS mechanisms specified in [RFC6004], [RFC4208], and [RFC4974].
 Support for Point-to-Point (P2P) and Multipoint-to-Multipoint (MP2MP)
 service is required by [G.8011] and [MEF11].  P2P service delivery
 support is based on the GMPLS support for Ethernet services covered
 in [RFC6004].  As with [RFC6004], the definition of support for MP2MP
 service is left for future study and is not addressed in this
 document.
 [MEF11] defines multiple types of control for UNI Ethernet services.
 In MEF UNI Type 1, services are configured manually.  In MEF UNI Type
 2, services may be configured manually or via a link management
 interface.  In MEF UNI Type 3, services may be established and

Berger & Fedyk Standards Track [Page 4] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

 managed via a signaling interface.  As with [RFC6004], this document
 is aimed at supporting the MEF UNI Type 3 mode of operation (and not
 MEF UNI Types 1 and 2).  As mentioned above, this document is limited
 to covering UNI-specific topics.
 Common procedures used to signal Ethernet connections are described
 in Section 2 of this document.  Procedures related to signaling
 switching in support of EPL services are described in Section 3.
 Procedures related to signaling switching in support of EVPL services
 are described in Section 4.

1.2. Conventions Used in This Document

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
 document are to be interpreted as described in [RFC2119].

2. Common Signaling Support

 This section describes the common mechanisms for supporting a UNI
 reference point for LSPs that provide the Ethernet Services described
 in [RFC6004].
 Except as specifically modified in this document, the procedures
 related to the processing of Resource ReSerVation Protocol (RSVP)
 objects is not modified by this document.  The relevant procedures in
 existing documents, notably [RFC6002], [RFC6004], [RFC4208], and
 [RFC4974], MUST be followed in all cases not explicitly described in
 this document.

2.1. UNI Addressing

 LSPs providing Ethernet connections controlled via the mechanisms
 defined in this document MUST use the addressing and other procedures
 defined in [RFC4208].  Of note, this includes the use of the egress
 edge node's IP address in the endpoint address field in the SESSION
 object.
 One issue that presents itself with the addressing approach taken in
 [RFC4208] is that an ingress edge node may not receive the egress
 edge node's IP address as part of the management, or other, request
 that results in the initiation of a new Ethernet connection.  This
 case is covered as described in Section 7.2 of [RFC4974] and modified
 below in Section 2.2.1.

Berger & Fedyk Standards Track [Page 5] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

2.2. Ethernet Endpoint (UNI) Identification

 UNI identification, except as noted below, MUST follow Ethernet
 endpoint (UNI) identification as defined in [RFC6004].  There is one
 additional case that is covered in this document where the scope of
 the Ethernet endpoint identifier is relevant beyond the typical case
 of just ingress and egress nodes.

2.2.1. Address Resolution

 At the UNI reference point, it is possible for the ingress edge node
 to not have the egress edge node's IP address when initiating an LSP.
 This presents an issue as the egress edge node's IP address is
 carried in the SESSION object.  This case is handled leveraging the
 approach described in Section 7.2 of [RFC4974] to address call ID
 assignment by the first core node.
 When an edge node (the UNI-C) initiates an LSP and it has the egress
 Ethernet endpoint identifier, but does not have its IP address, the
 edge node MUST create a Notify message as described in [RFC4974].
 The Notify message MUST include the CALL_ATTRIBUTES object with the
 Endpoint ID TLV defined [RFC6004].  The tunnel endpoint address field
 of the SESSION object in the Notify message MUST be set to zero (0).
 The message MUST be addressed and sent to an address associated with
 the first core node.
 When a core node, i.e., the node providing the network side of the
 UNI (the UNI-N), receives a Notify message with the tunnel endpoint
 address field of the SESSION object set to zero, it MUST locate the
 Endpoint ID TLV in the CALL_ATTRIBUTES object.  If the object or TLV
 are not present, the node MUST discard the message.  In this case, a
 Message ID Acknowledgment MUST NOT be sent for the Notify message.
 When the Endpoint ID TLV is located, the node MUST map the Endpoint
 ID into an IP address associated with the egress edge node.  If the
 node is unable to obtain an egress address, it MUST issue an error
 response Notify messages according to Section 6.2.2. of [RFC4974].
 The Error code and value SHOULD be "Routing Problem/Unknown Endpoint"
 (Error code 24, Error value 35).
 When the node is able to obtain an egress address, the endpoint
 address field of the SESSION object MUST be set to the obtained
 address, and the Notify message should be sent according to the
 standard processing defined in [RFC4974].  The downstream nodes will
 then process the Notify according to standard processing rules.

Berger & Fedyk Standards Track [Page 6] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

 When the ingress receives the response Notify message, it SHOULD
 identify the call based on the Endpoint ID TLV and, when not set to
 zero on the corresponding setup Notify message, the short and long
 Call IDs.  The endpoint address field of the SESSION object carried
 in the response Notify message will include the egress's IP address.
 This returned address MUST be used in all subsequent messages
 associated with the Ethernet connection.
 Note that the procedure described in this section MAY be used when
 the Call IDs are generated by the initiating UNI or generated by the
 first core node.

2.3. Connection Identification

 With one exception, UNI signaling for Ethernet connections MUST
 follow the Connection Identification procedures defined in [RFC6004].
 The exception is that the procedures defined in Section 7.2 of
 [RFC4974] MAY be used to provide support for allocation of Call IDs
 by the first core node rather than by the initiating edge node.

3. EPL Service

 There are no additional UNI-specific requirements for signaling LSPs
 supporting Ethernet Private Line (EPL) services.  The procedures
 defined in [RFC6004], as modified above, MUST be followed when
 signaling an LSPs supporting an EPL Service.

4. EVPL Service

 There is one additional UNI-specific requirement for signaling LSPs
 supporting an EVPL type service as described in Section 4.1.  Except
 as modified above and by this section, the procedures defined in
 [RFC6004] MUST be followed when signaling an EVPL Service.

4.1. Egress VLAN ID Control and VLAN ID Preservation

 Per [MEF6], the mapping of the single VLAN ID used at the ingress UNI
 to a different VLAN ID at the egress UNI is allowed for EVPL services
 that do not support both bundling and VLAN ID preservation.  Such a
 mapping MUST be requested and signaled based on the explicit label
 control mechanism defined in [RFC4208], and not the mechanisms
 defined in [RFC6004].
 As is the case in [RFC6004], when the explicit label control
 mechanism is not used VLAN IDs MUST be preserved, i.e., not modified,
 across the LSP.

Berger & Fedyk Standards Track [Page 7] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

5. IANA Considerations

 IANA has assigned new values for namespaces defined in this document
 and summarized in this section.

5.1. Error Value: Routing Problem/Unknown Endpoint

 IANA has made the following assignment in the "Error Codes and
 Globally-Defined Error Value Sub-Codes" section of the "RSVP
 Parameters" registry located at http://www.iana.org:
 Error Code      Meaning
   24  Routing Problem                             [RFC3209]
 Under "This Error Code has the following globally-defined Error
        Value sub-codes:"
       35 =  Unknown Endpoint                      [RFC6005]

6. Security Considerations

 This document makes use of the mechanisms defined in [RFC6004] and
 [RFC4974].  It does not in itself change the security models offered
 in each.  (Note that the address resolution discussed in Section 2.2
 above, parallels the replacement of information that occurs per
 Section 7.2 of [RFC4974].)  See [RFC6004] and [RFC4974] for the
 security considerations that are relevant to and introduced by the
 base mechanisms used by this document.

7. References

7.1. Normative References

 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119, March 1997.
 [RFC3209]  Awduche, D., Berger, L., Gan, D., Li, T., Srinivasan, V.,
            and G. Swallow, "RSVP-TE: Extensions to RSVP for LSP
            Tunnels", RFC 3209, December 2001.
 [RFC4208]  Swallow, G., Drake, J., Ishimatsu, H., and Y. Rekhter,
            "Generalized Multiprotocol Label Switching (GMPLS) User-
            Network Interface (UNI): Resource ReserVation Protocol-
            Traffic Engineering (RSVP-TE) Support for the Overlay
            Model", RFC 4208, October 2005.

Berger & Fedyk Standards Track [Page 8] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

 [RFC4974]  Papadimitriou, D. and A. Farrel, "Generalized MPLS (GMPLS)
            RSVP-TE Signaling Extensions in Support of Calls", RFC
            4974, August 2007.
 [RFC6002]  Berger, L. and D. Fedyk, "Generalized MPLS (GMPLS) Data
            Channel Switching Capable (DCSC) and Channel Set Label
            Extensions", RFC 6002, October 2010.
 [RFC6004]  Berger, L. and D. Fedyk, "Generalized MPLS (GMPLS) Support
            for Metro Ethernet Forum and G.8011 Ethernet Service
            Switching", RFC 6004, October 2010.

7.2. Informative References

 [G.8011]   ITU-T G.8011/Y.1307, "Ethernet over Transport Ethernet
            services framework", August 2004.
 [G.8011.1] ITU-T G.G.8011.1/Y.1307.1, "Ethernet private line
            service", August 2004.
 [G.8011.2] ITU-T G.8011.2/Y.1307.2, "Ethernet virtual private line
            service", September 2005.
 [MEF6]     The Metro Ethernet Forum, "Ethernet Services Definitions -
            Phase I", MEF 6, June 2004.
 [MEF10.1]  The Metro Ethernet Forum, "Ethernet Services Attributes
            Phase 2", MEF 10.1, November 2006.
 [MEF11]    The Metro Ethernet Forum , "User Network Interface (UNI)
            Requirements and Framework", MEF 11, November 2004.

Acknowledgments

 Dimitri Papadimitriou provided substantial textual contributions to
 this document and coauthored earlier versions of this document.
 The authors would like to thank Evelyne Roch and Stephen Shew for
 their valuable comments.

Berger & Fedyk Standards Track [Page 9] RFC 6005 GMPLS Support for MEF and G.8011 UNI October 2010

Authors' Addresses

 Lou Berger
 LabN Consulting, L.L.C.
 Phone: +1-301-468-9228
 EMail: lberger@labn.net
 Don Fedyk
 Alcatel-Lucent
 Groton, MA 01450
 Phone: +1-978-467-5645
 EMail: donald.fedyk@alcatel-lucent.com

Berger & Fedyk Standards Track [Page 10]

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