> I have the following scenario intermittently: The flow was too corrupted to adequately understand what was occurring. I'll assume that the 18x responses are truly retries (i.e. same To tag and RSeq). I assume that the single 200 is for PRACK; however I'm not sure who you are indicating sent it.
Is the second PRACK a retry or being sent by the SBC? If PRACK sent by the SBC, does it correctly correspond to the 18x? If PRACK not sent by the SBC, was the PRACK received by the SBC valid? > The service provider is stating they the SBC should send a PRACK for > every 183 sent, which I believe is correct however RFC3262 states "a > UAC SHOULD NOT retransmit the PRACK request when it receives a > retransmission of the provisional response being acknowledged" Assuming that the 18x responses are truly retries, RFC 3262 indicates (as you quoted) that the PRACK retries are independent of the 18x retries. Thus the PRACK "SHOULD NOT" be retransmitted upon receiving a 18x retry. > As far as I am concerned the PRACK is not being received by the Service > provider so they re-transmit the 183, which should be PRACK'd to stop > re-transmissions of the 183, but the RFC contradicts this As I mentioned, the flow was too corrupted to see if you were indicating that the PRACK reached the service provider and to see who sent the 200 response (SBC or service provider). The PRACK retries are independent of the 18x retries. _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
