Subject: [SIP] messages

From: Nils Henrik Lorentzen <[email-masked]>
Date: Wed, 28 Mar 2001 14:47:02 +0200

Hi,

I have a question regarding ordering of messages in the same calleg.
Is there some case where a UAC should allow/handlerequests
other than CANCEL that
are received while calleg's current transaction is not yet done ?
For example if we have a ongoing call and an UAC get
an INFO message, and before that transaction is done
we get a new INFO message, should we then just ignore the last one ?

For INVITEs the bis02 draft says one must send
a 400 response in the case comparable to the above..

For REGISTER it says:

"Registrations with the same Call-ID MUST have increasing
CSeq header values. However, the server does not reject
out-of-order requests."

AFAI can understand, this means:
Ignore out-of-order request,. Ie. do not send a failed-response,
but not try to process it either.
Is this a correct interpretation ?

What about requests other than INVITE and REGISTER ?

Also, what about requests coming in the opposite direction ?
Say in a statefull proxy, if it is forking, and have
sent a request through a calleg, and then receives
a non-CANCEL request on that same calleg before it receives a
response. How should it react to this ?
I know that the request it receives will belong to a different transaction,
so should one just try to forward it ?

Well, a lot of (probably stupid) questions, but please bear with me...

Nils Henrik

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