1. Using SAML for SIP H. Tschofenig, J. Peterson, J. Polk, D. Sicker, M. Tegnander

2. Overview presents — a problem statement — scenarios and — requirements Using Security Assertion Markup Language (SAML) in collaboration with SIP provides a solution for trait-based authorization.

3. Draft Content - In a Nutshell Three parties: — User — Asserting Party (creates Assertions/Artifact) = "Authentication Server" — Relying Party (verifies Assertions/Artifact) SAML Push Model — Uses Assertions in a "Call by value" style SAML Pull Model — Uses Artifacts in a "Call by reference" style Two ways of attaching the Assertions/Artifacts — Separate exchange with the Authentication Server — SIP messages traverse Authentication Server

4. Open Issues (1) Issue: — Reference integrity of SAML Assertions and SIP sessions Proposal: — Reuse existing work by Jon Issue: — Where should the Assertions be attached? Proposal: — SIP UA adds Assertions in body; SIP proxies add them by reference (Artifacts) in the SIP header

5. Open Issue (2) Issue: — Artifact should include a URL to enable easier dereference Proposal: — Change it with the next version of the draft Issue: — Option-tags need to be introduced (required / supported option-tag) Proposal: — Add them with the next version

6. Open Issue (3) Further issues: — Relationship with Liberty Alliance — More details for the described scenarios Please send comments!

7. Questions?