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<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">We’re having intermittent problems receiving calls from a particular DID. The basic scenario is as follows:</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Carrier sends invite w/SDP</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">We respond w/OK and SDP when call is answered</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Carrier sends another invite with incremented sequence number and updated SDP (are</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">n</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">t</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> they supposed to ACK/respond before doing this?)</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">We send</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">SIP 500</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">-</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">overlapping requests</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Carrier sends BYE - terminating the call</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Sometimes (rarely) the call completes, most of the time FS sends a 500 and doesn’t get the call. This</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">just</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">started happening recently and does not occur with any other DIDs, including other DIDs from the same carrier. I updated to the latest stable GIT to see if that might solve the problem but I’m pretty sure this is on the carrier’s end. They’re</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">trying to</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">blam</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">e</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> it on us since we’re sending the 500</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri"> and suggested that we allow overlapping requests</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">.</FONT></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">I</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">m assuming that their end needs to acknowledge our answer OK/SDP before sending their own but if that</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">s the problem then it raises another question in my mind: since the SIP transport is generally UDP, what if we don</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">t receive their ACK before receiving their</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">subsequent invite/SDP? This could certainly happen and would cause the call to be rejected if the above is true.</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">I updated to the latest stable GIT last night to rule</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">that out as a possible cause of the problem. Is there a way to get</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">FS to allow a limited number of overlapping requests</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">as a possible workaround</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">?</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">If</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">someone thinks</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">this looks like</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">it could be</FONT></SPAN><SPAN LANG="en-us"> <FONT FACE="Calibri">an FS bug, I</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">’</FONT></SPAN><SPAN LANG="en-us"><FONT FACE="Calibri">ll file a Jira.</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Here is a trace which shows this happening:</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN><A HREF="http://pastebin.freeswitch.org/22769"><SPAN LANG="en-us"><U><FONT COLOR="#0000FF" FACE="Calibri">http://pastebin.freeswitch.org/22769</FONT></U></SPAN><SPAN LANG="en-us"></SPAN></A><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT FACE="Calibri">Thanks,</FONT></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><I></I></SPAN><SPAN LANG="en-us"><I></I></SPAN><I><SPAN LANG="en-us"></SPAN></I><I><SPAN LANG="en-us"><FONT FACE="Times New Roman">Phil Quesinberry</FONT></SPAN></I><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN><SPAN LANG="en-us"></SPAN></P>
<P DIR=LTR><SPAN LANG="en-us"><FONT SIZE=2 FACE="Arial">Q Systems Engineering, Inc.</FONT></SPAN></P>
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