I'm seeing some peculiar behavior from sipXtapi, both from my application and when I use the PlaceCall utility. I'm using a version built with MSVS .Net 2003, from revision 9921 of the sipXtapi branch, along with my patch fixing a bug in the initialization of the list of DNS servers (the patch was submitted to the sipXtapi-dev list on 2007-07-31). I'm running the tests on Windows XP.
If I invoke PlaceCall as PlaceCall -S stun.example.org -i sip:[EMAIL PROTECTED] sip:[EMAIL PROTECTED] I see the following events in the WireShark packet capture: 1. STUN queries for UDP ports 5060, 9000 and 9001 and the corresponding replies. Nothing surprising so far. 2. A set of DNS queries for the SIP server being called (in this case interop.pingtel.com). The only unusual thing about the DNS queries is the UDP port number they are sent from: the first query uses an arbitrary port number (say 1168), and each subsequent DNS query increments the source UDP port number by one (1169, 1170, ...). 3. Then I get a sequence of three packets: a STUN query for the UDP source port number one higher than that used by the last DNS query, the STUN response to this query, and then a SIP packet with an INVITE request. The SIP packet uses this same source UDP port as the preceding STUN query (one higher than the last DNS query), but the SDP contained in it directs the reply to the IP:Port number returned by the original STUN response for UDP source port 5060. 4. This repeats a few times, except that the source UDP port for the STUN query and outgoing SIP invite increases by 1 each time. Any suggestions of where to look for the problem? Stephen C. Steel _______________________________________________ sipxtapi-dev mailing list [email protected] List Archive: http://list.sipfoundry.org/archive/sipxtapi-dev/
