Subject: BYE terminating pending INVITE transaction

From: Lars Berggren <[email-masked]>
Date: Wed, 15 Sep 1999 10:20:28 +0200

Hi.

See
http://www.cs.columbia.edu/~hgs/sip/drafts/draft-ietf-mmusic-sip-new-00.pdf,
section 4.2.4.

"A BYE request from either called or calling party terminates any
pending INVITE,but the INVITE request transaction MUST be completed with
a final response."

This does not seem to match the state diagram for the INVITE method in
figure 13, if the server receives a BYE in the 'call proceeding' state.

Shouldn't there be a dedicated response code for this scenario, 487?

If a client sends a BYE to an INVITE that is pending, and the BYE
completes first, it waits for the INVITE transaction to complete. If it
completes with a 2xx status, how should the state of the call be
interpreted by the client? As I interpret SIP, the call is released due
to the fact that the BYE has a higher cseq value. The time of completion
is not of significance, right? Anyway, this scenario seems to be
unlikely to happen and the client will probably send another BYE after
it receives that 2xx response.

/Lars.

-- 
Lars Berggren       <[email-masked]>
Intertex Data AB    tel: +46-8-6282828
Sundbyberg, Sweden  fax: +46-8-6286414

---

From: Jonathan Rosenberg <[email-masked]>
Date: Wed, 15 Sep 1999 10:50:23 -0400

> figure 13, if the server receives a BYE in the 'call proceeding' state.

This needs to be updated to be consistent.

> Shouldn't there be a dedicated response code for this scenario, 487?

Its not critical, but 487 makes sense.

> it receives that 2xx response.

If the BYE completes with a 200 OK, the call is over, regardless of
whether the BYE response or INVITE response arrives first. As you say,
it is the CSeq ordering which is important, not the order of arrival of
responses. Sending another BYE won't help, as this will be responded to
with a 481 (I think) indicating that no such call exists.

-Jonathan R.
-- 
Jonathan D. Rosenberg                       Lucent Technologies
Member of Technical Staff                   101 Crawfords Corner Rd.
High Speed Networks Research                Holmdel, NJ 07733
FAX:   (732) 834-5379                       Rm. 4C-526
EMAIL: [email-masked]
URL: http://www.cs.columbia.edu/~jdrosen