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New Member

SIP Trunk bewteen 2 cucm clusters - fast busy tone

Hi all

I have created a sip trunk between 2 cucm servers, the calls seem to work one way just fine, however when they try to call me they get a fast busy tone!

any ideas whereI should look to fix this ?





Did you reset the trunks?

Did you reset the trunks?

HTH Regards, Yosh
New Member



Did you add all CUCM IPs for

Did you add all CUCM IPs for the remote cluster on your ICT? CUCM wont accept calls from subscribers whose IP is not in its DB.

Please rate useful posts.

What is the CUCM version of

What is the CUCM version of both sides?

Also please verify if you have checked the option 'Run On All Active Nodes'. If so, please uncheck it and see if it helps.


As George said, If the call from cluster A is made with originating IP address x.x.x.x and if this address x.x.x.x is not defined as the destination in cluster B to A, then the calls will not be accepted.


if the CUCM version is 8.x and above, you can login into RTMT tool and check the session trace for the failed call. It will display the SIP message flow for the call. with the cause code, we can further troubleshoot it.


If the configurations looks good, please attach the CCM traces for the call failure with calling number, called number & time of call.



Please rate all the helpful posts

//Suresh Please rate all the useful posts.