----- Original Message -----
Sent: Wednesday, March 13, 2002 10:00
PM
Subject: RE: [Sip-implementors] Via
branch in ACK for 200?
hi,
I guess the question being asked here is more from a client
perspective
of what an UAC is supposed to do while sending an ACK
back.. for a non-2xx final response...
As mentioned earlier, the spec makes it clear for an ACK being sent for a
non-2xx final response
as having to have the branch parameter in Via (17.1.1.3) same as that of
the INVITE request
as this ACK will belong to the same transaction.
But an ACK for 2xx final response, will be a new transaction in itself
and thus as per the spec should
have a unique branch parameter, which the UAC would need to
construct. But now again the UAS
does'nt really have to do anything about it as an ACK does'nt solicit a
response. So the branch may
not really be of any use.
Could we get some more clarity on this.
Rama
Brett Tate <[EMAIL PROTECTED]> wrote:
>
In ACK generated by client transaction for non-200 responses
> the
bis clearly states that the topmost Via should be used
> when
constructing the ACK request. What about the ACK
> generated for
200 OK? I guess that this kind of ACK should
> have a unique Via
branch ( not matching the ACKed INVITE's
> branch) but I couldn't
clearly derive it from bis. Could
> someone please clarify what is
the correct behaviour ?
After sending a 200 response, the UAS/proxy
cannot rely upon the branch being the
same because the prior proxy
might not
have added itself to the record-route.
Thus it ultimately
should not make a
difference either way.
> ATTACHMENT part 2
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