[SR-Users] Wrong handling CANCEL message

Klaus Darilion klaus.mailinglists at pernau.at
Fri Apr 30 11:49:39 CEST 2010



Am 30.04.2010 11:37, schrieb Iñaki Baz Castillo:
> 2010/4/30 Klaus Darilion<klaus.mailinglists at pernau.at>:
>> 200 OK seems correct as long as the transaction is still in memory.
>>
>> http://tools.ietf.org/html/rfc3261#section-9.2
>
> I don't agree. As per RFC 3261 when a proxy receives a 200 for an
> INVITE the transaction is terminated so a CANCEL after the 200 should
> not match such transaction. Then the proxy should reply 481 to the
> CANCEL rather than a 200.


    If the transaction
    for the original request still exists, the behavior of the UAS on
    receiving a CANCEL request depends on whether it has already sent a
    final response for the original request.

This means that the transaction may still exists although the 200 OK was 
already sent (to absorb retransmissions)

    Regardless of the method of the original request, as long as the
    CANCEL matched an existing transaction, the UAS answers the CANCEL
    request itself with a 200 (OK) response.

So 200 OK is fine. If it makes sense is a different point.

regards
klaus




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