Update to the Session Initiation Protocol (SIP) Preconditions Framework
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From: The IESG <email@example.com> To: IETF-Announce <firstname.lastname@example.org> Cc: Internet Architecture Board <email@example.com>, RFC Editor <firstname.lastname@example.org>, sip mailing list <email@example.com>, sip chair <firstname.lastname@example.org> Subject: Protocol Action: 'Update to the Session Initiation Protocol (SIP) Preconditions Framework' to Proposed Standard The IESG has approved the following document: - 'Update to the Session Initiation Protocol (SIP) Preconditions Framework ' <draft-ietf-sip-rfc3312-update-04.txt> as a Proposed Standard This document is the product of the Session Initiation Protocol Working Group. The IESG contact persons are Allison Mankin and Jon Peterson. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-sip-rfc3312-update-04.txt
Technical Summary This document updates the framework for preconditions in SIP. It clarifies RFC 3312; it does not obsolete RFC 3312, but just explains it better and adds some rules that update it. It provides guidelines for authors who plan to write new precondition types, beyond the qos precondition. In addition, this document describes and solves some issues concerning the interaction between session mobility and preconditions. Working Group Summary The working group supported advancement of this document. Protocol Quality The concerns about session mobility were identified in implementation experiences. The document was reviewed for the IESG by Allison Mankin and by Spencer Dawkins of the General Area Review Team. RFC Editor Notes Abstract: OLD: This document updates the framework for preconditions in SIP. NEW: This document updates RFC 3312, which defines the framework for preconditions in SIP. Add the following paragraph to the end of the Introduction: Specifically, we now allow answers to downgrade current status values (this was disallowed by RFC 3312). We consider moving an existing stream to a new location as equivalent to establishing a new stream. Therefore, answerers moving streams to new locations set all the current status values in their answers to "No" and start a new precondition negotiation from scratch. Section 4.1 OLD: Table 3 of RFC 3312  needs to be updated to allow answers to downgrade current status values. NEW: Table 3 of RFC 3312 needs to be updated to allow answerers to downgrade current status values. Section 6 IANA Considerations OLD: This document has no IANA considerations. NEW: The IANA registration requirements for the preconditions framework are defined in RFC 3312. Any new preconditions are governed by the IANA Considerations there. Throughout the document: After the first reference to , omit the .