SIP Trunk Cannot Make Outbound Calls

Unanswered Question
Apr 13th, 2010

I am currently experiencing some routing issues with SIP Trunks.

Here is some background information.

I have a CUCM version 7.01 utilizing an internal SIP Trunk to an IVR (server).  I am having trouble making outbound calls from the IVR (via the SIP trunk) to a PRI Trunk group.  The PRI Trunk group is connected to a CO simulator (Hammer), which through scripting will answer the calls.  I can make an outbound call through the PRI Trunk group from an IP phone or SIP phone connected to the CUCM but if I try to initiate an outbound call from the IVR using the SIP trunk, the call fails.
This is a Lab environment so there is no Calling Search Space setup.

Any help would be greatly appreciated.

Thank you...Frank
I have this problem too.
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gogasca Fri, 04/16/2010 - 11:41

I would check SIP port, IP addresses, Security Profile to make sure Protocol specified is correct (TCP,UDP or TLS)

and significant number of digits in SIP trunk,


Cn you upload CUCM traces so we can check

Include calling,called number, timestamps and call details

fkramarski Mon, 04/19/2010 - 12:57

Hi gogasca,

Thank you for the reply.

The SIP trunks are fully functional with the exception of dialing out the PRI trunks.

This will be my first go around pulling trace files that are not TSP related traces.  Can you provide a little info on what traces would be helpful and how to enable/capture them?

Thanx again...Frank

malnaima Fri, 09/17/2010 - 13:34

Hello Frank,

Can you kindly shed some light on the scenario as it's not that clear;


- the PRI's are located on a GW what is the connection between GW and CM ?

- you say calls from IVR fail; does the IVR initiate the call "the application" or is this an IVR part of a customer responce solution with agents that are initiating the calls via the trunk ?

- what is the codec used accross the complete scenario ?

- when the call fails what do u get ? ex; fast busy ?

By the way traces can be enabled and collected according to the following:

Best Regards,


Steven Holl Mon, 09/20/2010 - 08:17

Can you get these debugs for a failure:

debug isdn q931

debug voip ccapi inout

debug ccsip mess

Also post the output of 'sh run'.  If the PRI and SIP gateways are different devices, please collect that information from both devices for the call.


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