> From: Markus Hofmann [mailto:[EMAIL PROTECTED] > > There is the same Call-ID, same from tag and CSeq number is > the same. The UAS should be able to recognise that this is a > retransmission and should send its last answer (200 OK).
*No*, the Call-Id, From-tag, and CSeq are *not* enough to detect retransmission -- you have to check the branch-parameter of the top Via as well. Otherwise, if you have received two forks of the same INVITE (say), you will think they are duplicates, when they are not -- each must be responded to separately. This is the *single most common error* we have found when testing SIP phones. In ordinary office situations, it can cause inexplicable difficulties for the users. Dale _______________________________________________ Sip-implementors mailing list [email protected] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
