8 Mar
2007
8 Mar
'07
10:27 a.m.
Andrew T Gin wrote:
Hi
I have two questions.
1. Receiver(a)1.1.1.1 and Receiver(a)2.2.2.2 register with ser.
Client sends an INVITE to ser for Receiver.
ser forks these INVITES in parallel to both Receiver(a)1.1.1.1 and
Receiver(a)2.2.2.2.
As both Receivers are online, they both reply with 200 OK.
SER then relays BOTH 200 OK's back to the Client.
My question: Shouldn't SER send CANCEL to one of the receivers, and
relay only ONE 200 OK back to the client? How would I do this?
It is not the client's responsibility to send a CANCEL to the SER to
relay to one of the receivers, is this correct? This is because the
client only sent one invite, therefore it should only receive one OK. ie
should SER 'shield' the client from the knowledge of the existence of
multiple contact addresses?
No, the 2xx responses must be forwarded to the client as the INVITE
transaction cannot be canceled once a final response has been
generated by the UAS. Moreover, the proxy would not know _which_
call leg to cancel (which peer is the one the caller wants to talk to?)
Thus, it _is_ the client's responsibility to send a BYE for the call
it wants to finish (note that it cannot be canceled at that state).
Regards,
Olaf