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<div class=Section1>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>I’m testing SIP trunking connectivity to an ITSP
through a Covergence (CXC)/ACME Packet session border controller. Calls from an
IP phone to the PSTN through SER and the CXC are being dropped 15 seconds after
the initial call is setup and just after a cal l is answered. We do not have
this problem with calls which reach the PSTN via local gateways. It seems that
SER is not relaying an ACK which it receives from the phone which causes the
SBC to resend a 200 OK message until finally the connection times out. I’ve
checked the call routing and do not see any issue however I do notice the
following in the SER logs.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: --ACK--: Time: [Thu Aug 13 13:07:24
2009] From: <<a href="sip:89390@vidar.net.isc.upenn.edu">sip:89390@vidar.net.isc.upenn.edu</a>>
To <<a href="sip:92155738396@vidar.net.isc.upenn.edu;user=phone">sip:92155738396@vidar.net.isc.upenn.edu;user=phone</a>>
Src IP <128.91.2.223> Method:<ACK> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: [Thu Aug 13 13:07:24 2009]
[453a4bbf-90848c86-ea3a8091@128.91.56.18] <<a
href="sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp">sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp</a>>
Starting PRESENCE/BLA section <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: [Thu Aug 13 13:07:24 2009]
[453a4bbf-90848c86-ea3a8091@128.91.56.18] <<a
href="sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp">sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp</a>>
End PRESENCE/BLA section <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: [Thu Aug 13 13:07:24 2009]
[453a4bbf-90848c86-ea3a8091@128.91.56.18] --URI match--. Method: <ACK>
R-uri: <<a
href="sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp">sip:92155738396@vidar.net.isc.upenn.edu:5060;user=phone;maddr=128.91.56.242;transport=udp</a>>
Contact Header: <<<a href="sip:89390@128.91.56.18:5060">sip:89390@128.91.56.18:5060</a>>>
From: <<a href="sip:89390@vidar.net.isc.upenn.edu">sip:89390@vidar.net.isc.upenn.edu</a>>
To <<a href="sip:92155738396@vidar.net.isc.upenn.edu;user=phone">sip:92155738396@vidar.net.isc.upenn.edu;user=phone</a>>
IP source address <128.91.2.223> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: --ACK--: Time: [Thu Aug 13 13:07:24
2009] From: <<a href="sip:89390@vidar.net.isc.upenn.edu">sip:89390@vidar.net.isc.upenn.edu</a>>
To <<a href="sip:92155738396@vidar.net.isc.upenn.edu;user=phone">sip:92155738396@vidar.net.isc.upenn.edu;user=phone</a>>
Src IP <128.91.2.223> Method:<ACK> <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: [SER]: Too many hops <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Aug 13 13:07:24 vidar
/usr/local/sbin/ser[19053]: Warning: sl_send_reply: I won't send a reply for
ACK!!<o:p></o:p></span></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>User 89390 is a local subscriber and the phone initiating
the call. The recipient of the call is my desk phone 215-573-8396 which is on a
different, unrelated SER service. <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>We do record_route traffic through SER for call control and
accounting reasons. It seems like the ACK is looping through SER and therefore
never being sent to the SBC but I cannot see why. Does anyone have any thoughts
on this issue?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Thanks,Steve<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
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