> Does this implies that UAS can send 200 OK final response to initial INVITE > before receiving the PRACK for the unacknowledged provisional response > without SDP?
Yes. > If the above scenario is possible than when should UAS free the RPR > transaction as the RFC 3262 states that UAS should be able to process the > PRACK for the unacknowledged provisional response even after sending the > final response. My interpretation of the following is that the 64*T1 timer continues for transaction cleanup even though retries should not continue. However, it mostly depends upon how you interpret "prepared to process" in relation to the infamous 2xx versus 481 paragraph. My interpretation is overly influenced by RFC 5057 indicating to destroy the dialog usage upon receiving PRACK 481 instead recommending behavior similar to CANCEL 481. "If the UAS does send a final response when reliable responses are still unacknowledged, it SHOULD NOT continue to retransmit the unacknowledged reliable provisional responses, but it MUST be prepared to process PRACK requests for those outstanding responses." "If a PRACK request is received by the UA core that does not match any unacknowledged reliable provisional response, the UAS MUST respond to the PRACK with a 481 response. If the PRACK does match an unacknowledged reliable provisional response, it MUST be responded to with a 2xx response. The UAS can be certain at this point that the provisional response has been received in order. It SHOULD cease retransmissions of the reliable provisional response, and MUST remove it from the list of unacknowledged provisional responses." _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
