Hello, We are making a firewall ALG and we have a question about the tag or maddr param of the Contact header specifically in non REGISTER messages that contain Record-Route headers.
Here is the scenario: - we receive an INVITE from the caller with the Caller's Contact - we add a ";tag=..." (or ";maddr=...") value to the Contact header (inside <>'s) - we add a Record-Route header (and do other stuff for Vias, etc) - we send the INVITE to the next hop proxy (or the callee) (we receive and proxy "100 Trying" and "180 Ringing" responses) - we receive a 200 OK from the callee with the callee's Contact - we add ";tag=..." (or ";maddr=...") to the Contact header (inside <>'s) - we send the 200 OK to the caller - we receive an ACK from the caller with Route entries - the last Route entry does not always have our ";tag=..." param! The implementation from UA Vendor A does not retain the param that we added to the Contact header ... the Route header does not contain ";tag=...". We also see that the implementation from UA Vendor B does keep the param we added. Our question is which implementation is correct? To get around the problem, we instead change the user portion of the Contact URI to contain our tag value. This isn't our first choice, but appears to work without any problems ... but we are not sure if this is a legal thing to do either. Thoughts, suggestions? Ching-Der Wang _______________________________________________ Sip-implementors mailing list [EMAIL PROTECTED] http://lists.cs.columbia.edu/mailman/listinfo/sip-implementors
