Scenario#32 – SIP Calls drop after 75 minutes

I had an interesting case where SIP calls over a SIP trunk were dropping after like 75 minutes. The duration was not confirmed as sometimes it use to drop even before 75 minutes. I looked into few CCSIP debugs (debug ccsip messages) and found that the ‘BYE’ message was actually coming from our end (Call manager/Gateway). Platform information: CCM: System version: 7.1.3.32900-4 CUBE-10#sh ver Cisco IOS Software, 3800 Software (C3825-ADVIPSERVICESK9-M), Version 12.4(24)T4, RELEASE SOFTWARE (fc2) Technical Support: http://www.cisco.com/techsupport Copyright (c) 1986-2010 by Cisco Systems, Inc. Compiled Fri 03-Sep-10 09:15 by prod_rel_team ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1) CUBE-10 … Continue reading Scenario#32 – SIP Calls drop after 75 minutes

Scenario#24 – SIP Calls drop after Silence

Came across a complex situation where customer was using this SIP trunk as an alternative to ISDN-30 (if all channels are used or if ISDN goes down). The ISDN-30 link was working fine but they had issues on SIP trunk (how many times I have heard this?) …. their outbound calls over SIP were using a prefix ‘8’ to route calls on SIP trunk to SIP Provider. The Outbound calls were working fine. The inbound calls drop after 8 secs and none of the calling/called party could hear each other. Complete silence.. Call flow was something like this: PSTN (81763)  … Continue reading Scenario#24 – SIP Calls drop after Silence