see inline
----- Original Message -----
From: "Janarthanan, Bhagatram" <[EMAIL PROTECTED]>
> Hi ,
> The draft draft-ietf-sip-100-rel06 specifies that
>
> Quote
> � After the first reliable provisional response for a request has been
> acknowledged, the UAS MAY send additional reliable provisional responses.
> The UAS MAY send a final response to the initial request before having
> recevied PRACKs for all unacknowleged reliable provisional responses,
> unless
> the final response is 2xx and any of the unacknowleged reliable
> provisional
> responses contained a session description.
> UnQuote
>
> Because of the above, a scenario like this at UaC is possible
>
> UaC
> -----INV-------------------->
> <---1XX-(RSeq=45)-Reliable---
> ----PRACK------------------->
> <---200-(PRACK)--------------
> <---200-(INVITE)-------------
> <---1XX-(RSeq=46)-Reliable---
>
> In this case, should the SIP layer at the UaC,
> (a) drop the second 1xx
> (b) send a prack for second 1xx, but not inform the application above
> SIP
> about the second 1xx (since, the second 1xx didnot contain sdp
> information)
The spec does not say that the UAS is allowed to send a reliable provisional
response after having sent the final response. What it is allowing is this:
UaC
-----INV-------------------->
<---1XX-(RSeq=45)-Reliable---
<---200-(INVITE)-------------
----PRACK------------------->
<---200-(PRACK)--------------
The UAS does not have to wait for the PRACK before sending its final
response. However, it is possible that the UAC might "receive" a subsequent
1XX after the 2XX (due to UDP retransmissions or re-ordering). In which
case, your option (b) is the right thing to do.
_______________________________________________
Sip-implementors mailing list
[EMAIL PROTECTED]
http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
