SESSION-ID Backward COMPATIBILITY 2012-09-27 SESSION-ID Backward COMPATIBILITY Christer Holmberg INSIPID Interim, October 4th 2012 © Ericsson AB 2012

TERMINOLOGY KAPLAN ENTITY INSIPID ENTITY Implementing draft-kaplan-dispatch-session-id Draft-00 referenced by 3GPP Transfer case not covered (introduced in -02) Draft-03 latest Must decide which version to use as base for backward compatibility INSIPID ENTITY Implementing the to-be-defined INSIPID mechanism “2 part” session identifier value Both endpoints contribute to the session identifier value

ABNF KAPLAN ENTITY INSIPID ENTITY Session-ID = "Session-ID" HCOLON sess-id *( SEMI generic-param ) sess-id = 32(DIGIT / %x61-7A) ; 32 chars of [0-9a-z] draft-00 sess-id = 32(DIGIT / %x61-66) ; 32 chars of [0-9a-f] draft-03 INSIPID ENTITY Re-usage of KAPLAN syntax: Part 1: sess-id Part 2: generic-param Session-ID:f81d4fae7dec11d0a76500a0c91e6bf6;param=dd5tder11d0a76500a0c91e6bf6

ABNF: RETRIEVED REQUIREMENTS REQ-SYN-1: The INSIPID session identifier syntax MUST be backward compatible with the syntax in draft-kaplan-session-id-XX. Header field name and value REQ-SYN-2: An INSIPID entity MUST be prepared to receive a session identifier generated by a KAPLAN entity. No remote part added in the SIP response.

UA Behavior: KAPLAN UAC UAS “The UAC MUST re-use the same Session-ID for in-dialog messages, and for any out-of- dialog request it retransmits or re-generates in response to a 3xx, or it re-formulates due to failure responses.” Draft-03: same Session-ID value: Out of dialog REFER Refer-To header field must contain Session-ID value as embedded header field Out of dialog INVITE with Replaces header field Reason: retain value during transfer Multiple SIP dialogs with same value UAS “A UAS compliant with this document MUST copy a received Session-ID value in a request, into responses and subsequent upstream requests sent within the dialog.”

UA: RETRIEVED REQUIREMENTS REQ-UA-1: It MUST be possible for an INSIPID entity to detect that it is communicating with a KAPLAN entity. The INSIPID entity does not add its own part to a received session identifier REQ-UA-2: An INSIPID entity, when communicating with a KAPLAN entity, MUST NOT modify the Session-Id value within a dialog. Not in a response, nor in a mid-dialog request

NEXT STEP BASED ON OUTCOME OF DISCUSSIONS, SUBMIT NEW VERSION OF ”DRAFT-KAPLAN”.

THANK YOU!