Technical Summary
This specification defines mechanisms by which a Session Initiation
Protocol (SIP) user agent can convey its capabilities and
characteristics to other user agents and to the registrar for its
domain. This information is conveyed as parameters of the Contact
header field. It may be used by a proxy for call routing. The parameter
design is based on RFC 2506, media feature tags. The specification
creates a SIP tree registry parallel to the IETF tree registry from
RFC 2506. The syntax of the parameters is based on RFC 2533.
Strong considerations regarding the privacy and data
integrity of the information are discussed by the document.
Working Group Summary
The working group took a lot of care and review developing this design.
There was a mid-course design review from an Applications area
standpoint that resulted in the advice to work with the RFC 2533,
2506 approach, which has proved to be very constructive. The WG
supported the advancement strongly, after thorough review.
Protocol Quality
The document was reviewed for the IESG by Allison Mankin. The
Applications mid-course reviews were by Patrik Faltstrom and Ted
Hardie.