SESSIONID Backward COMPATIBILITY Christer Holmberg INSIPID Interim October

SESSION-ID Backward COMPATIBILITY Christer Holmberg INSIPID Interim, October 4 th 2012

TERMINOLOGY › KAPLAN ENTITY – Implementing draft-kaplan-dispatch-session-id › Draft-00 referenced by 3 GPP - 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 Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 2

ABNF KAPLAN ENTITY Session-ID = "Session-ID" HCOLON sess-id *( SEMI generic-param ) sess-id = 32(DIGIT / %x 61 -7 A) ; 32 chars of [0 -9 a-z] 32(DIGIT / %x 61 -66) ; 32 chars of [0 -9 a-f] draft-00 draft-03 INSIPID ENTITY Re-usage of KAPLAN syntax: Part 1: Part 2: sess-id generic-param Session-ID: f 81 d 4 fae 7 dec 11 d 0 a 76500 a 0 c 91 e 6 bf 6; param=dd 5 tder 11 d 0 a 76500 a 0 c 91 e 6 bf 6 Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 3

ABNF: RETRIEVED REQUIREMENTS › REQ-SYN-1: REQ-SYN-1 The INSIPID session identifier syntax MUST be backward compatible with the syntax in draft-kaplansession-id-XX. – Header field name and value › REQ-SYN-2: 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. Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 4

UA Behavior: KAPLAN › UAC – “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 3 xx, or it reformulates 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. ” Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 5

UA: RETRIEVED REQUIREMENTS › REQ-UA-1: 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: 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 Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 6

NEXT STEP › BASED ON OUTCOME OF DISCUSSIONS, SUBMIT NEW VERSION OF ”DRAFT-KAPLAN”. Public | © Ericsson AB 2012 | 2012 -09 -27 | Page 7