Name that User John Elwell Cullen Jennings Venkatesh Venkataramanan draft-elwell-sip-state-update-00 draft-jennings-sipping-connected-00 draft-ietf-sipping-qsig2sip-04 RFC 3325

Problem Need names that User Agents can display to Users We have a proliferation of Identity related data containers, ways to transport them, and times they can be changed, and entities that can change them No one know what any of the mean. Most of them are very ill defined. They don’t meet needs identified

Requirements - Are they right? Need a way for SIP to indicate the identify of the user at the other end of a session (for both ends) Identity changes during a call (both in early dialog and in dialog) Biloxi proxy may know (from mutual TLS) that the call is from Atlanta proxy even though it can’t verify it is from Alice. Want transitive trust (like sips url). The entity sending believes this information because: –It has some way of figuring out it is true –It received it from someone it is configured to believe –It modified the information to match its belief Information is subject to Privacy Works even if user does not have a certificate.Not every user has a certificate. If they did, not everyone else could get it. If they could, what it asserts may not be useful.

Can changing To/From work Allow Proxy to change To/From Add tag to indicate trust ? Allowing this to change would break 2543 transaction matching. –Does this matter

What about a Name header Add a new header called Name with clearly defined semantic meaning Can be in Request or Response Represents identity of sender or message Can be changed/add/del by Proxy Privacy ID applies to it (Like From/To) Has flag to indicate it is not trusted? Use UPDATE with no SDP to change mid dialog.

Does PAI meet the requirements Write extensions to semantics and meaning of PAI to extend it to meet the needs Has a really difficult problem –PAI is removed as you pass into a new 3325 trust domain Trust Dom ATrust Dom B ABCD

Non-Solutions SipFrag –Can’t be added, changed, by proxy –Solutions where proxy tells UA to add a body might work S/MIME –Can’t have GW have certificates for all PSTN users. –No way to get the certificates to make this work

Recommendation Clean up the Name mess. Provide guidance on which of the many identities a UA receives that it might want to display to a User. Clarify using Update/Re-Invite in dialog