GENWiki

Premier IT Outsourcing and Support Services within the UK

User Tools

Site Tools


rfc:rfc8262

Internet Engineering Task Force (IETF) C. Holmberg Request for Comments: 8262 I. Sedlacek Updates: 5368, 5621, 6442 Ericsson Category: Standards Track October 2017 ISSN: 2070-1721

  Content-ID Header Field in the Session Initiation Protocol (SIP)

Abstract

 This document specifies the Content-ID header field for usage in the
 Session Initiation Protocol (SIP).  This document also updates RFC
 5621, which only allows a Content-ID URL to reference a body part
 that is part of a multipart message-body.  This update enables a
 Content-ID URL to reference a complete message-body and metadata
 provided by some additional SIP header fields.
 This document updates RFC 5368 and RFC 6442 by clarifying their usage
 of the SIP Content-ID header field.

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 7841.
 Information about the current status of this document, any errata,
 and how to provide feedback on it may be obtained at
 https://www.rfc-editor.org/info/rfc8262.

Holmberg & Sedlacek Standards Track [Page 1] RFC 8262 Content-ID in SIP October 2017

Copyright Notice

 Copyright (c) 2017 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
 (https://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.  Identifying a Body Part . . . . . . . . . . . . . . . . .   3
   1.2.  Referencing a Body Part . . . . . . . . . . . . . . . . .   3
   1.3.  Problem Statement . . . . . . . . . . . . . . . . . . . .   4
   1.4.  Consequences  . . . . . . . . . . . . . . . . . . . . . .   4
     1.4.1.  Example 1: SIP INVITE . . . . . . . . . . . . . . . .   4
     1.4.2.  Example 2: SIP REFER  . . . . . . . . . . . . . . . .   6
   1.5.  Solution  . . . . . . . . . . . . . . . . . . . . . . . .   7
   1.6.  Backward Compatibility  . . . . . . . . . . . . . . . . .   7
 2.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . .   7
 3.  Content-ID Header Field . . . . . . . . . . . . . . . . . . .   8
   3.1.  Introduction  . . . . . . . . . . . . . . . . . . . . . .   8
   3.2.  Syntax  . . . . . . . . . . . . . . . . . . . . . . . . .   8
   3.3.  Semantics . . . . . . . . . . . . . . . . . . . . . . . .   8
   3.4.  Procedures  . . . . . . . . . . . . . . . . . . . . . . .   9
     3.4.1.  User Agent (UA) Procedures  . . . . . . . . . . . . .   9
     3.4.2.  Proxy Procedures  . . . . . . . . . . . . . . . . . .   9
     3.4.3.  Example: Referencing the Message-Body of a SIP
             Message . . . . . . . . . . . . . . . . . . . . . . .   9
 4.  Update to RFC 5368  . . . . . . . . . . . . . . . . . . . . .  10
 5.  Update to RFC 5621  . . . . . . . . . . . . . . . . . . . . .  11
 6.  Update to RFC 6442  . . . . . . . . . . . . . . . . . . . . .  11
 7.  Security Considerations . . . . . . . . . . . . . . . . . . .  12
 8.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .  12
   8.1.  Header Field  . . . . . . . . . . . . . . . . . . . . . .  12
 9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .  13
   9.1.  Normative References  . . . . . . . . . . . . . . . . . .  13
   9.2.  Informative References  . . . . . . . . . . . . . . . . .  14
 Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .  14

Holmberg & Sedlacek Standards Track [Page 2] RFC 8262 Content-ID in SIP October 2017

1. Introduction

1.1. Identifying a Body Part

 A SIP message consists of a start-line, one or more header fields, an
 empty line indicating the end of the header fields, and an optional
 message-body as specified in [RFC3261].
 The message-body can be a non-multipart message-body or a multipart
 message-body as specified in [RFC3261].
 [RFC5621] defines generic handling of a multipart message-body in a
 SIP message.
 A multipart message-body contains zero, one, or several body parts
 encoded using the format define in [RFC2045].
 A body part in the multipart message-body is described using header
 fields such as Content-Disposition, Content-Encoding, and Content-
 Type, which provide information on the content of the body part as
 specified in [RFC5621].  A body part in the multipart message-body
 can also contain a Content-ID header field with an ID value uniquely
 identifying the body part as specified in [RFC2045].

1.2. Referencing a Body Part

 A SIP header field can reference a body part using a Content-ID URL
 as specified in [RFC5621].
 The Content-ID URL is specified in [RFC2392].  [RFC2392] specifies
 how to identify the body part referenced by a Content-ID URL.  The
 Content-ID URL value is included in the Content-ID header field of
 the body part.
 Examples of SIP header fields referencing a body part using a
 Content-ID URL are:
 o  [RFC6442] specifies how a Geolocation header field references a
    body part using a Content-ID URL for providing location
    information.
 o  [RFC5368] specifies how a Refer-To header field references a body
    part using a Content-ID URL to provide a list of targets.

Holmberg & Sedlacek Standards Track [Page 3] RFC 8262 Content-ID in SIP October 2017

1.3. Problem Statement

 How to uniquely identify a complete message-body of a SIP message
 using a Content-ID header field and how to reference a complete
 message-body using a Content-ID URL are not currently specified.
 Note: In [RFC5621], the Content-ID URL references a specific body
 part only.
 Some existing specifications, such as [RFC5368], contain examples
 that show usage of a SIP Content-ID header field referencing a
 complete message-body, even though such usage has never been
 specified.  Many implementors have interpreted these examples to
 indicate that such usage is allowed by the corresponding
 specification, despite the absence of language allowing it.  This
 document updates the normative language in the affected documents to
 explicitly allow such usage.

1.4. Consequences

 The examples below show the consequences of the problem described
 above.

1.4.1. Example 1: SIP INVITE

 If a User Agent Client (UAC) sends an INVITE request that conveys
 location by value (as specified in [RFC6442]) and decides not to
 include a Session Description Protocol (SDP) offer, then the UAC
 needs to include only one MIME entity in the INVITE request.  This
 MIME entity can be, for example, of the 'application/pidf+xml' MIME
 type.
 However, due to [RFC6442] requiring inclusion of a Geolocation header
 field referencing the body part with the location information, the
 UAC includes a multipart message-body with a single body part in the
 INVITE request, and includes the location information of
 'application/pidf+xml' MIME type and an associated Content-ID header
 field in the body part.

Holmberg & Sedlacek Standards Track [Page 4] RFC 8262 Content-ID in SIP October 2017

   Example message (SIP INVITE):
   INVITE sips:bob@biloxi.example.com SIP/2.0
   Via: SIPS/2.0/TLS pc33.atlanta.example.com;branch=z9hG4bK74bf9
   Max-Forwards: 70
   To: Bob <sips:bob@biloxi.example.com>
   From: Alice <sips:alice@atlanta.example.com>;tag=9fxced76sl
   Call-ID: 3848276298220188511@atlanta.example.com
   Geolocation: <cid:target123@atlanta.example.com>
   Geolocation-Routing: no
   Accept: application/sdp, application/pidf+xml
   CSeq: 31862 INVITE
   Contact: <sips:alice@atlanta.example.com>
   Content-Type: multipart/mixed; boundary=boundary1
   Content-Length: ...
  1. -boundary1

Content-Type: application/pidf+xml

   Content-ID: <target123@atlanta.example.com>
   <?xml version="1.0" encoding="UTF-8"?>
   <presence
     xmlns="urn:ietf:params:xml:ns:pidf"
     xmlns:gp="urn:ietf:params:xml:ns:pidf:geopriv10"
     xmlns:gbp="urn:ietf:params:xml:ns:pidf:geopriv10:basicPolicy"
     xmlns:cl="urn:ietf:params:xml:ns:pidf:geopriv10:civicAddr"
     xmlns:gml="http://www.opengis.net/gml"
     xmlns:dm="urn:ietf:params:xml:ns:pidf:data-model"
     entity="pres:alice@atlanta.example.com"
     >
     <dm:device id="target123-1">
       <gp:geopriv>
         <gp:location-info>
           <gml:location>
             <gml:Point srsName="urn:ogc:def:crs:EPSG::4326">
               <gml:pos>32.86726 -97.16054</gml:pos>
             </gml:Point>
           </gml:location>
         </gp:location-info>
         <gp:usage-rules>
           <gbp:retransmission-allowed>no
           </gbp:retransmission-allowed>
           <gbp:retention-expiry>2010-11-14T20:00:00Z
           </gbp:retention-expiry>
         </gp:usage-rules>
         <gp:method>802.11</gp:method>
       </gp:geopriv>

Holmberg & Sedlacek Standards Track [Page 5] RFC 8262 Content-ID in SIP October 2017

       <dm:deviceID>mac:1234567890ab</dm:deviceID>
       <dm:timestamp>2010-11-04T20:57:29Z</dm:timestamp>
     </dm:device>
   </presence>
   --boundary1--

1.4.2. Example 2: SIP REFER

 If a UAC sends a REFER request including a list of targets as
 specified in [RFC5368], then the UAC needs to include only one MIME
 entity in the REFER request.  This MIME entity is of the
 'application/resource-lists+xml' MIME type.
 However, due to [RFC5368] requiring inclusion of a Refer-To header
 field referencing the body part containing the list of targets, the
 UAC includes a multipart message-body with a single body part in the
 REFER request and includes the list of targets of 'application/
 resource-lists+xml' MIME type and an associated Content-ID header
 field in the body part.
  Example message (SIP REFER):
  REFER sip:conf-123@example.com;gruu;opaque=hha9s8d-999a  SIP/2.0
  Via: SIP/2.0/TCP client.chicago.example.com;branch=z9hG4bKhjhs8ass83
  Max-Forwards: 70
  To: "Conference 123" <sip:conf-123@example.com>
  From: Carol <sip:carol@chicago.example.com>;tag=32331
  Call-ID: d432fa84b4c76e66710
  CSeq: 2 REFER
  Contact: <sip:carol@client.chicago.example.com>
  Refer-To: <cid:cn35t8jf02@example.com>
  Refer-Sub: false
  Require: multiple-refer, norefersub
  Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
  Allow-Events: dialog
  Accept: application/sdp, message/sipfrag
  Content-Type: multipart/mixed; boundary=boundary1
  Content-Length: ...
  1. -boundary1

Content-Type: application/resource-lists+xml

  Content-Disposition: recipient-list
  Content-ID: <cn35t8jf02@example.com>

Holmberg & Sedlacek Standards Track [Page 6] RFC 8262 Content-ID in SIP October 2017

  <?xml version="1.0" encoding="UTF-8"?>
  <resource-lists
    xmlns="urn:ietf:params:xml:ns:resource-lists"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    >
    <list>
      <entry uri="sip:bill@example.com?method=BYE"/>
      <entry uri="sip:joe@example.org?method=BYE"/>
      <entry uri="sip:ted@example.net?method=BYE"/>
    </list>
  </resource-lists>
  --boundary1--

1.5. Solution

 In order to solve the problems described above, this document:
 o  Specifies and registers the Content-ID header field as a SIP
    header field.
 o  Specifies that, when used as a SIP header field, the Content-ID
    header field identifies the complete message-body and the metadata
    provided by some additional SIP header fields of the SIP message.
 o  Updates [RFC5621] to enable a Content-ID URL to reference a
    complete message-body and the metadata provided by some additional
    SIP header fields.
 o  Updates [RFC5368] and [RFC6442] by adding text that explicitly
    states that a SIP Content-ID header field can be used.

1.6. Backward Compatibility

 If an existing specification only defines the usage of a multipart
 message-body to carry a single body part to be referenced by a
 Content-ID URL, implementations MUST NOT carry the MIME entity in a
 non-multipart message-body unless the specification is updated to
 explicitly allow it.

2. Conventions

 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
 "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
 "OPTIONAL" in this document are to be interpreted as described in BCP
 14 [RFC2119] [RFC8174] when, and only when, they appear in all
 capitals, as shown here.

Holmberg & Sedlacek Standards Track [Page 7] RFC 8262 Content-ID in SIP October 2017

3. Content-ID Header Field

3.1. Introduction

 This section defines the usage of the Content-ID header field for
 SIP.

3.2. Syntax

 The ABNF [RFC5234] for the Content-ID header field is:
  Content-ID = "Content-ID" HCOLON msg-id
  msg-id     = "<" id-left "@" id-right ">"
  Note: id-left and id-right are specified in [RFC5322]. HCOLON is
  defined in [RFC3261].
  Note: When used in a SIP header field, the msg-id syntax has been
  simplified, compared to the syntax in [RFC5322], to disallow the use
  of comments and to adopt to the SIP usage of leading white space.
  The value of the Content-ID header field value must be unique in the
  context of a given SIP message, including any embedded MIME
  Content-ID header field values. Note that the SIP Content-ID header
  field value is not expected to be unique among all SIP messages; it
  has no meaning outside of the message in which it is included.

3.3. Semantics

 The Content-ID header field included in the header fields of a SIP
 message identifies the message-body of the SIP message and the
 metadata provided by:
 o  A MIME-Version header field, if included in the header fields of
    the SIP message.
 o  Any 'Content-' prefixed header fields (including the Content-ID
    header field itself) included in the header fields of the SIP
    message.
 The Content-ID header field can be included in any SIP message that
 is allowed to contain a message-body.
 Note: The message-body identified by the Content-ID header field can
 be a non-multipart message-body or a multipart message-body.

Holmberg & Sedlacek Standards Track [Page 8] RFC 8262 Content-ID in SIP October 2017

3.4. Procedures

3.4.1. User Agent (UA) Procedures

 A UA MAY include a Content-ID header field in any SIP message that is
 allowed to contain a message-body.
 A UA MUST NOT include a Content-ID header field in any SIP message
 that is not allowed to contain a message-body.
 A UA MUST set the value of the Content-ID header field to a value
 that is unique in the context of the SIP message.

3.4.2. Proxy Procedures

 A proxy MUST NOT add a Content-ID header field in a SIP message.
 A proxy MUST NOT modify a Content-ID header field included in a SIP
 message.
 A proxy MUST NOT delete a Content-ID header field from a SIP message.

3.4.3. Example: Referencing the Message-Body of a SIP Message

 The figure shows an example from [RFC5368], where the SIP Content-ID
 header field is used to reference the message-body (non-multipart) of
 a SIP message.
 REFER sip:conf-123@example.com;gruu;opaque=hha9s8d-999a  SIP/2.0
 Via: SIP/2.0/TCP client.chicago.example.com
         ;branch=z9hG4bKhjhs8ass83
 Max-Forwards: 70
 To: "Conference 123" <sip:conf-123@example.com>
 From: Carol <sip:carol@chicago.example.com>;tag=32331
 Call-ID: d432fa84b4c76e66710
 CSeq: 2 REFER
 Contact: <sip:carol@client.chicago.example.com>
 Refer-To: <cid:cn35t8jf02@example.com>
 Refer-Sub: false
 Require: multiple-refer, norefersub
 Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY
 Allow-Events: dialog
 Accept: application/sdp, message/sipfrag
 Content-Type: application/resource-lists+xml
 Content-Disposition: recipient-list
 Content-Length: 362
 Content-ID: <cn35t8jf02@example.com>

Holmberg & Sedlacek Standards Track [Page 9] RFC 8262 Content-ID in SIP October 2017

 <?xml version="1.0" encoding="UTF-8"?>
 <resource-lists xmlns="urn:ietf:params:xml:ns:resource-lists"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
   <list>
     <entry uri="sip:bill@example.com?method=BYE" />
     <entry uri="sip:joe@example.org?method=BYE" />
     <entry uri="sip:ted@example.net?method=BYE" />
   </list>
 </resource-lists>

4. Update to RFC 5368

 This section updates the second paragraph in Section 7 of [RFC5368]
 by allowing usage of either a MIME Content-ID header field or a SIP
 Content-ID header field to label the body part or the message-body
 carrying the URI list.
 OLD TEXT:
    The Refer-To header field of a REFER request with multiple REFER-
    Targets MUST contain a pointer (i.e., a Content-ID Uniform
    Resource Locator (URL) as per RFC 2392 [RFC2392]) that points to
    the body part that carries the URI list.  The REFER-Issuer SHOULD
    NOT include any particular URI more than once in the URI list.
 NEW TEXT:
    The Refer-To header field of a REFER request with multiple REFER-
    Targets MUST contain a pointer (i.e., a Content-ID Uniform
    Resource Locator (URL) as per RFC 2392 [RFC2392]) that points to
    the body part or message-body that carries the URI list.  The
    REFER-Issuer SHOULD NOT include any particular URI more than once
    in the URI list.  The REFER request can use either a MIME Content-
    ID header field [RFC4483] or a SIP Content-ID header field
    [RFC8262] to label the body part or the message-body.

Holmberg & Sedlacek Standards Track [Page 10] RFC 8262 Content-ID in SIP October 2017

5. Update to RFC 5621

 This section updates Section 9.1 of [RFC5621] by allowing a Content-
 ID URL to reference a message-body and the related metadata
 (Section 3.3) in addition to allowing a reference to a body part.
 OLD TEXT:
    Content-ID URLs allow creating references to body parts.  A given
    Content-ID URL [RFC2392], which can appear in a header field or
    within a body part (e.g., in an SDP attribute), points to a
    particular body part.
 NEW TEXT:
    Content-ID URLs allow the creation of references to body parts or
    message-bodies (and the header fields describing the message-
    bodies).  A given Content-ID URL [RFC2392], which can appear in a
    header field or within a body part (e.g., in an SDP attribute),
    points to a particular body part or the message-body (and the
    header fields describing the message-body).

6. Update to RFC 6442

 This section updates the second paragraph in Section 3.1 of [RFC6442]
 by allowing usage of either a MIME Content-ID header field or a SIP
 Content-ID header field to label the body part or the message-body
 carrying the location data.
 OLD TEXT:
    In Figure 1, Alice is both the Target and the LS that is conveying
    her location directly to Bob, who acts as an LR.  This conveyance
    is point-to-point: it does not pass through any SIP-layer
    intermediary.  A Location Object appears by-value in the initial
    SIP request as a MIME body, and Bob responds to that SIP request
    as appropriate.  There is a 'Bad Location Information' response
    code introduced within this document to specifically inform Alice
    if she conveys bad location information to Bob (e.g., Bob "cannot
    parse the location provided", or "there is not enough location
    information to determine where Alice is").

Holmberg & Sedlacek Standards Track [Page 11] RFC 8262 Content-ID in SIP October 2017

 NEW TEXT:
    In Figure 1, Alice is both the Target and the LS that is conveying
    her location directly to Bob, who acts as an LR.  This conveyance
    is point-to-point: it does not pass through any SIP-layer
    intermediary.  A Location Object appears by-value in the initial
    SIP request as a MIME body, and Bob responds to that SIP request
    as appropriate.  Either a MIME Content-ID header field [RFC4483]
    or the SIP Content-ID header field [RFC8262] MUST be used to label
    the location information.  There is a 'Bad Location Information'
    response code introduced within this document to specifically
    inform Alice if she conveys bad location information to Bob (e.g.,
    Bob "cannot parse the location provided", or "there is not enough
    location information to determine where Alice is").

7. Security Considerations

 The Content-ID header field value MUST NOT reveal sensitive user
 information.
 If the message-body associated with the Content-ID header field is an
 encrypted body, it MUST NOT be possible to derive a key that can be
 used to decrypt the body from the Content-ID header field value.

8. IANA Considerations

 This specification registers a new SIP header field according to the
 procedures defined in [RFC3261].

8.1. Header Field

 The header field described in Section 3 has been registered in the
 "Header Fields" sub-registry of the "Session Initiation Protocol
 (SIP) Parameters" registry by adding a row with these values:
    Header Name: Content-ID
    compact:
    Reference: RFC 8262

Holmberg & Sedlacek Standards Track [Page 12] RFC 8262 Content-ID in SIP October 2017

9. References

9.1. Normative References

 [RFC2045]  Freed, N. and N. Borenstein, "Multipurpose Internet Mail
            Extensions (MIME) Part One: Format of Internet Message
            Bodies", RFC 2045, DOI 10.17487/RFC2045, November 1996,
            <https://www.rfc-editor.org/info/rfc2045>.
 [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
            Requirement Levels", BCP 14, RFC 2119,
            DOI 10.17487/RFC2119, March 1997,
            <https://www.rfc-editor.org/info/rfc2119>.
 [RFC2392]  Levinson, E., "Content-ID and Message-ID Uniform Resource
            Locators", RFC 2392, DOI 10.17487/RFC2392, August 1998,
            <https://www.rfc-editor.org/info/rfc2392>.
 [RFC3261]  Rosenberg, J., Schulzrinne, H., Camarillo, G., Johnston,
            A., Peterson, J., Sparks, R., Handley, M., and E.
            Schooler, "SIP: Session Initiation Protocol", RFC 3261,
            DOI 10.17487/RFC3261, June 2002,
            <https://www.rfc-editor.org/info/rfc3261>.
 [RFC4483]  Burger, E., Ed., "A Mechanism for Content Indirection in
            Session Initiation Protocol (SIP) Messages", RFC 4483,
            DOI 10.17487/RFC4483, May 2006,
            <https://www.rfc-editor.org/info/rfc4483>.
 [RFC5234]  Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
            Specifications: ABNF", STD 68, RFC 5234,
            DOI 10.17487/RFC5234, January 2008,
            <https://www.rfc-editor.org/info/rfc5234>.
 [RFC5322]  Resnick, P., Ed., "Internet Message Format", RFC 5322,
            DOI 10.17487/RFC5322, October 2008,
            <https://www.rfc-editor.org/info/rfc5322>.
 [RFC5621]  Camarillo, G., "Message Body Handling in the Session
            Initiation Protocol (SIP)", RFC 5621,
            DOI 10.17487/RFC5621, September 2009,
            <https://www.rfc-editor.org/info/rfc5621>.
 [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
            2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
            May 2017, <https://www.rfc-editor.org/info/rfc8174>.

Holmberg & Sedlacek Standards Track [Page 13] RFC 8262 Content-ID in SIP October 2017

9.2. Informative References

 [RFC5368]  Camarillo, G., Niemi, A., Isomaki, M., Garcia-Martin, M.,
            and H. Khartabil, "Referring to Multiple Resources in the
            Session Initiation Protocol (SIP)", RFC 5368,
            DOI 10.17487/RFC5368, October 2008,
            <https://www.rfc-editor.org/info/rfc5368>.
 [RFC6442]  Polk, J., Rosen, B., and J. Peterson, "Location Conveyance
            for the Session Initiation Protocol", RFC 6442,
            DOI 10.17487/RFC6442, December 2011,
            <https://www.rfc-editor.org/info/rfc6442>.

Authors' Addresses

 Christer Holmberg
 Ericsson
 Hirsalantie 11
 Jorvas  02420
 Finland
 Email: christer.holmberg@ericsson.com
 Ivo Sedlacek
 Ericsson
 Sokolovska 79
 Praha  18600
 Czech Republic
 Email: ivo.sedlacek@ericsson.com

Holmberg & Sedlacek Standards Track [Page 14]

/data/webs/external/dokuwiki/data/pages/rfc/rfc8262.txt · Last modified: 2017/10/26 00:10 by 127.0.0.1

Donate Powered by PHP Valid HTML5 Valid CSS Driven by DokuWiki