1. Extending the Session Initiation Protocol (SIP) Reason Header for Applications draft-mohali-sipcore-reason-extension-application-00 draft-mohali-sipcore-reason-extension-application-00 Marianne Mohali (marianne.mohali@orange-ftgroup.com)marianne.mohali@orange-ftgroup.com Bruno Chatras (bruno.chatras@orange-ftgroup.com)

2. Problem statement –As per RFC 3326: Reason header field may be present to indicate why a SIP request was issued. Problem: –Applications may initiate rejection or cancellation of SIP request –but cannot include an application-specific reason in the CANCEL/BYE request.

3. Problem statement (contd.) –As per RFC 4244: Reason header field may be present in the History- Info header to indicate why a SIP request was retargeted. Problem: –Existing protocol-cause values do not permit sending application-specific reasons

4. Proposed solution Allow the use of Reason header field in application- initiated SIP requests Extension similar to RFC4411 (preemption) By creating: –a new protocol value: "application" –a new set of associated cause values: protocol protocol-cause reason-text -------------- ------------------ ----------------- application cause=x text="xxxx" Example: Reason:application;cause=2;text="Freephone"

5. Use case Alice Freephone Server INVITE History-Info: [Reason:application;cause=2;text="Freephone"] Agent INVITE Call is retargeted

6. Early Comments/feedbacks Issue 1: Add a cause value for forking needs? => Reason in CANCEL sent on the legs to release

7. Early Comments/feedbacks Issue 2: Add more readability in IANA section => done in the next version

8. Early Comments/feedbacks Issue 3: Improve cause values description => done in the next version

9. Next Steps –Need more reviewers –WG item? Intended status: standards track

10. Questions? Thank you !