--- 1/draft-ietf-sipcore-content-id-06.txt 2017-06-28 10:13:07.929003037 -0700 +++ 2/draft-ietf-sipcore-content-id-07.txt 2017-06-28 10:13:07.953003609 -0700 @@ -1,43 +1,45 @@ SIPCORE Working Group C. Holmberg Internet-Draft I. Sedlacek Updates: 5621 (if approved) Ericsson -Intended status: Standards Track June 5, 2017 -Expires: December 7, 2017 +Intended status: Standards Track June 28, 2017 +Expires: December 30, 2017 Content-ID header field in Session Initiation Protocol (SIP) - draft-ietf-sipcore-content-id-06 + draft-ietf-sipcore-content-id-07 Abstract This document specifies the Content-ID header field for usage in the Session Initiation Protocol (SIP). The document also updates RFC - 5621, to enable a Content-ID URL to reference a complete message-body - and metadata provided by some additional SIP header fields. + 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. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at http://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." - This Internet-Draft will expire on December 7, 2017. + This Internet-Draft will expire on December 30, 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 (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -48,38 +50,38 @@ described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1.1. Identifying a body part . . . . . . . . . . . . . . . . . 2 1.2. Referencing a body part . . . . . . . . . . . . . . . . . 3 1.3. Problem statement . . . . . . . . . . . . . . . . . . . . 3 1.4. Consequences . . . . . . . . . . . . . . . . . . . . . . 3 1.4.1. Example 1 . . . . . . . . . . . . . . . . . . . . . . 3 - 1.4.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . 4 - 1.5. Solution . . . . . . . . . . . . . . . . . . . . . . . . 4 - 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 4 - 3. Content-ID header field . . . . . . . . . . . . . . . . . . . 4 - 3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 4 - 3.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 3.3. Semantics . . . . . . . . . . . . . . . . . . . . . . . . 5 - 3.4. Procedures . . . . . . . . . . . . . . . . . . . . . . . 5 - 3.4.1. UA procedures . . . . . . . . . . . . . . . . . . . . 5 - 3.4.2. Proxy procedures . . . . . . . . . . . . . . . . . . 6 - 3.4.3. Example . . . . . . . . . . . . . . . . . . . . . . . 6 - 4. Update to RFC 5621 . . . . . . . . . . . . . . . . . . . . . 7 - 5. Security considerations . . . . . . . . . . . . . . . . . . . 8 - 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 8 - 6.1. Header field . . . . . . . . . . . . . . . . . . . . . . 8 - 7. Change log . . . . . . . . . . . . . . . . . . . . . . . . . 9 - 8. Normative references . . . . . . . . . . . . . . . . . . . . 9 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 + 1.4.2. Example 2 . . . . . . . . . . . . . . . . . . . . . . 5 + 1.5. Solution . . . . . . . . . . . . . . . . . . . . . . . . 6 + 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 3. Content-ID header field . . . . . . . . . . . . . . . . . . . 7 + 3.1. Introduction . . . . . . . . . . . . . . . . . . . . . . 7 + 3.2. Syntax . . . . . . . . . . . . . . . . . . . . . . . . . 7 + 3.3. Semantics . . . . . . . . . . . . . . . . . . . . . . . . 7 + 3.4. Procedures . . . . . . . . . . . . . . . . . . . . . . . 8 + 3.4.1. User Agent (UA) procedures . . . . . . . . . . . . . 8 + 3.4.2. Proxy procedures . . . . . . . . . . . . . . . . . . 8 + 3.4.3. Example . . . . . . . . . . . . . . . . . . . . . . . 8 + 4. Update to RFC 5621 . . . . . . . . . . . . . . . . . . . . . 9 + 5. Security considerations . . . . . . . . . . . . . . . . . . . 10 + 6. IANA considerations . . . . . . . . . . . . . . . . . . . . . 10 + 6.1. Header field . . . . . . . . . . . . . . . . . . . . . . 10 + 7. Change log . . . . . . . . . . . . . . . . . . . . . . . . . 11 + 8. Normative references . . . . . . . . . . . . . . . . . . . . 11 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 12 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 @@ -105,67 +107,159 @@ 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. + 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. 1.3. Problem statement It is currently not specified 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. NOTE: In [RFC5621], the Content-ID URL references a specific body part only. 1.4. Consequences The examples below shows the consequences of the problem described above. 1.4.1. Example 1 - If a UAC sends an INVITE request conveying location as specified in - [RFC6442], if the UAC decides not to include an SDP offer, and if the - location is conveyed by value, then the UAC needs to include only one - MIME entity in the INVITE request. This MIME entity can be e.g. of - the application/pidf+xml MIME type. + If a User Agent Client (UAC) sends an INVITE request conveying + location as specified in [RFC6442], if the UAC decides not to include + an SDP offer, and if the location is conveyed by value, 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 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. + 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 + From: Alice ;tag=9fxced76sl + Call-ID: 3848276298220188511@atlanta.example.com + Geolocation: + Geolocation-Routing: no + Accept: application/sdp, application/pidf+xml + CSeq: 31862 INVITE + Contact: + Content-Type: multipart/mixed; boundary=boundary1 + Content-Length: ... + + --boundary1 + Content-Type: application/pidf+xml + Content-ID: + + + + + + + + + 32.86726 -97.16054 + + + + + false + + 2010-11-14T20:00:00Z + + + 802.11 + + mac:1234567890ab + 2010-11-04T20:57:29Z + + + --boundary1-- + 1.4.2. Example 2 If a UAC sends an 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 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" + From: Carol ;tag=32331 + Call-ID: d432fa84b4c76e66710 + CSeq: 2 REFER + Contact: + Refer-To: + 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: ... + + --boundary1 + Content-Type: application/resource-lists+xml + Content-Disposition: recipient-list + Content-ID: + + + + + + + + + + --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; and o Specifies that, when used as a SIP header field, the Content-ID header field identifies the complete message-body, and metadata provided by some additional SIP header fields, of the SIP message; and @@ -208,39 +303,43 @@ 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; and + 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 which 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. + 3.4. Procedures -3.4.1. UA 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. - The UA MUST set the value of the Content-ID header field to a - globally unique value. + The 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. @@ -288,21 +387,21 @@ 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 creating references to body parts or + 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). 5. Security considerations The Content-ID header field value MUST NOT reveal sensitive user information. @@ -328,20 +427,25 @@ Header Name: Content-ID compact: Reference: RFCXXXX 7. Change log [RFC EDITOR NOTE: Please remove this section when publishing] + Changes from draft-ietf-sipcore-content-id-06 + + o Editorial changes and clarifications based on Gen-ART review from + Elwyn Davies. + Changes from draft-ietf-sipcore-content-id-05 o Changes based on AD comments from Ben Campell: o - Clarifying that Content-ID header field value is unique within the scope of a SIP message. Changes from draft-ietf-sipcore-content-id-04 o Minor editorial fix.