There is a slight difference in usage of ports in case of UDP and TCP. When a request is sent out via UDP, the Via header indicates the IP address and port number to which all the responses should be routed back. When TCP is used to send a request, the information in the Via header is overridden and response is routed back to the same IP address and port from the request was received from. This ensures that no additional TCP connection needs to be opened to send the response to a request that was received via TCP.
The UE however will set its protected server port in the Via header, regardless of UDP or TCP, Its just that, in case of UDP, response to such a request will be sent UE's protected server port as indicated in the Via Header. And in case of TCP, the responses to such a request will be sent to the UE's protected client port, as the request originated from there. -Bharat On Monday, February 10, 2014 11:15 AM, Aditya Kumar <adityakumar...@yahoo.com> wrote: Hi, when using IP-Sec and sending the subsequent SIP:REGISTER after receiving 401 challenge, I see that when UDP is used, the via is protected server port and when TCP the via is protected client port? any reason for the difference? if so can you please let me know.... _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors _______________________________________________ Sip-implementors mailing list Sip-implementors@lists.cs.columbia.edu https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
