I am not sure if that is a reasonable argument. This behavior has been
acknowledged as a bug in the RFC 3261. The bug detailes what the fix for the
same is going to be. I assume that this change in behavior will make it into
a RFC sometime in future. Not sure an example draft that contradicts this
behavior is a good idea.

For this specific scenario under consideration the far end is going to get a
200 OK for the CANCEL (instead of a 481 response). It is still going to have
to complete the INVITE transaction and tear down the call with a BYE.

Venkatesh


On 5/18/06, Frank Shearar <[EMAIL PROTECTED]> wrote:
>
> Sure, I agree that there's an open bug. Nonetheless, if you write a stack
> to
> fix the bug, then your stack isn't quite RFC 3261 compliant anymore. UACs
> that expect you to follow the RFC will then be surprised. (Caveat: I've
> not
> thought through what cases might lead to unexpected behaviour.)
>
> frank
>
> ----- Original Message -----
> From: "Venkatesh" <[EMAIL PROTECTED]>
> To: "Frank Shearar" <[EMAIL PROTECTED]>
> Cc: <[email protected]>
> Sent: Thursday, May 18, 2006 4:26 PM
> Subject: Re: [Sip-implementors] Question
> regardingdraft-hasebe-sipping-exceptional-procedure-examples-02.
>
>
> I meant the UAS is not supposed to terminate the INVITE transaction on
> sending a 200 OK response for the INVITE.
>
> On 5/18/06, Venkatesh <[EMAIL PROTECTED]> wrote:
> >
> >  Please refer to the bug I referred to in my previous email that is open
> > against RFC 3261. It clearly indicates that the UAS is not supposed to
> > terminate the INVITE transaction on sending a 200 OK response for the
> > response. If this were indeed to be the case, the UAS will still find
> the
> > INVITE transaction and that is my point.
> >
> > Venkatesh
> >
> >
> >  On 5/18/06, Frank Shearar <[EMAIL PROTECTED]> wrote:
> > >
> > > "Venkatesh" <[EMAIL PROTECTED]> wrote:
> > >
> > >
> > > > Section 2.1 of this draft illustrates a scenario where by a CANCEL
> and
> > > a
> > > 200
> > > > OK for the INVITE cross the wire. The draft suggests rejecting the
> > > CANCEL
> > > > with a 481 final response. I am not sure this is correct behavior.
> The
> > > UAS
> > > > must send a 200 OK for the CANCEL request (as it would find the
> INVITE
> > > > transaction). INVITE transacations are not supposed to be destroyed
> > > when a
> > > > 200 OK response for the INVITE is sent by the UAS. I believe there
> is
> > > a
> > > bug
> > > > open against RFC 3261 for the same (
> > > > http://bugs.sipit.net/show_bug.cgi?id=769)
> > >
> > > RFC section 9.2 says regarding a UAS processing a CANCEL request
> > >
> > >   If the UAS did not find a matching transaction for the CANCEL
> > >   according to the procedure above, it SHOULD respond to the CANCEL
> > >   with a 481 (Call Leg/Transaction Does Not Exist).
> > >
> > > In Hasebe et al's draft(*), Bob's 200 OK terminates his INVITE
> > > transaction.
> > > As a result, when Alice's CANCEL arrives, Bob cannot match the CANCEL
> > > against a transaction, so must return a 481.
> > >
> > > (*) The draft's name has changed to
> draft-hasebe-sipping-race-examples,
> > > and
> > > in the new draft this scenario is in section 3.1.2.
> > >
> > > frank
> > >
> > > _______________________________________________
> > > Sip-implementors mailing list
> > > [email protected]
> > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
> > >
> >
> >
>
> _______________________________________________
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