On 9/15/06, Colin Whittaker <[EMAIL PROTECTED]> wrote: > I'm not seeing any processing of the SDP when I receive multiple 183 > replies to my INVITE. > Also, the 200 OK SDP is not being processes either.
Are those 183 100rel responses (iow, are they PRACKed)? > This is a problem since my proxy is using this method to redirect a call > to a voice mail server. > I see a > nua(0x102db820): INVITE: ignoring duplicate SDP in 183 Session Progress > which I assume means the stack is not prepared for a new SDP after the > first one. > Is the proxy violating the spec ? Yes. The can be only one answer to a single offer. The proxy could fork the request, that is, it could respond from another logical endpoint, the change would be visible from another tag in the To header. However, that would bring other complications, like how to tell UAC that the previous fork should be dropped. I just yesterday called forking brain-dead. Not to mention that the nua stack does not dig forking after it has received a 183. If the proxy would like to keep existing dialog, it could send UPDATE with a new offer in it. > Would it be difficult to modify the stack to support this ? You could have peek in nua_session.c where the code now logs the message about duplicate sdp. However, you have to decide how to interpret the SDP. This is the most difficult part, I'm afraid. Standard is no help because O/A model tells us to ignore those SDP. Of course, you could peek in the User-Agent header in the response and make decision based on that. In the past we have interpreted these extra SDP in subsequent 183 or 200 as new offers, and sent answer in PRACK or ACK. -- Pekka.Pessi mail at nokia.com ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Sofia-sip-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/sofia-sip-devel
