Except for 100 (Trying), a 1xx should always be forwarded upstream toward the
UAC. Remember, all transactions complete independently. There may be a 2xx
final response right behind the 1xx response. The CANCEL can only change the
state of an INVITE transaction in the UAS.
In section 16.7 of RFC 3261, it says:
Until a final response has been sent on the server transaction,
the following responses MUST be forwarded immediately:
- Any provisional response other than 100 (Trying)
- Any 2xx response
cheers,
(-:bob
-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Iñaki Baz
Castillo
Sent: Friday, June 10, 2011 8:35 AM
To: Bob Penfield
Cc: [email protected]
Subject: Re: [Sip-implementors] About CANCEL in a proxy (no changes to
server/client transaction)
2011/6/10 Iñaki Baz Castillo <[email protected]>:
> 2011/6/10 Bob Penfield <[email protected]>:
>> Yes, in this case, a transaction stateful proxy should send a CANCEL to Bob
>> when the 1xx is received. Yes, you do need to save "state", but that can be
>> as simple as a flag in the client transaction that indicates a CANCEL should
>> be sent when a 1xx arrives.
>
> I did exactly that and already works :)
Just a question: In that case (late 1XX response which triggers the
CANCEL in the proxy), should the proxy route the 1XX response
upstream? note that the proxy has already received a CANCEL from the
caller.
I think that the proxy should relay such late 1XX response (due
specs), but I also think it's 100% useless.
--
Iñaki Baz Castillo
<[email protected]>
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
_______________________________________________
Sip-implementors mailing list
[email protected]
https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
