> -----Original Message-----
> From: Arunachalam Venkatraman [mailto:[EMAIL PROTECTED]]
> Sent: Wednesday, May 16, 2001 9:17 PM
> To: SIP Implementors
> Cc: Jonathan Rosenberg
> Subject: [Sip-implementors] Unsent Reliable Provisional
> Responses after
> final response
>
>
> I have re-formulated an earlier question with a better
> explanation (I hope!)
>
> In Section 6.3 of the 100-rel draft's 03 version, it is said -
>
> The UAS MUST NOT send a second reliable provisional
> response until the first is acknowledged. After the first, it is
> RECOMMENDED that the UAS not send an additional reliable
> provisional
> response until the previous is acknowledged.
>
>
> It is also said in the same section -
>
> A UAS MUST NOT send new
> reliable provisional responses (as opposed to retransmissions of
> outstanding ones) after sending a final response to a request.
>
>
> Suppose a UAS receives the following in rapid succession (or
> any other valid
> sequence of provisionals followed by 200)
Why would a UAS receive provisionals? A UAS sends them.
>
> 182 2 in Queue
> 182 1 in Queue
> 183 Session Progress
> 180 Ringing
> 2XX/3XX/ 4XX/5XX/6XX
>
> The final response may be available to be sent even before
> the PRACK to the
> first one is received.
> In that case, (based on the above extracts from the draft) the other
> provisional responses MUST not be sent.
>
> However, there may be useful information in the attachments
> (eg. ISUP INFO
> for SIP-T, with cause code) that should be
> conveyed reliably but cannot be sent.
If the UAS wants to send those provisionals reliably before sending the
final response, it can do so.
>
> If the final response is 200 OK, the attachment in that
> response is adequate
> and there should be no loss of information by dropping the provisional
> responses. But if the final response is a failure response,
> the attachment
> in an earlier 183 will have IEs that are required, for example, to
> correctly interpret the cause of the call failure.
>
> Should we queue up a non-200 final response to wait for the
> first PRACK?
That is an implementation decision.
-Jonathan R.
---
Jonathan D. Rosenberg, Ph.D. 72 Eagle Rock Ave.
Chief Scientist First Floor
dynamicsoft East Hanover, NJ 07936
[EMAIL PROTECTED] FAX: (973) 952-5050
http://www.jdrosen.net PHONE: (973) 952-5000
http://www.dynamicsoft.com
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