04-03-2025 01:49 AM
Hi everyone,
I’ve recently configured an Intercluster SIP Trunk between two CUCM clusters (Cluster A and Cluster B).
The SIP Trunk shows as "Active", but when I try to dial from a phone in Cluster A to a phone in Cluster B,
the call fails with a fast busy tone.
Any help would be appreciated
Solved! Go to Solution.
04-03-2025 01:53 AM
Hi @William Pacheco
i suggest to do this checklist:
1- Make sure the CSS assigned to the SIP Trunk in Cluster A includes the Partition of the phones (or translation patterns) in Cluster B
2- Make sure the number dialed from Cluster A matches the expected dial plan format in Cluster B
3- Double-check the following on the SIP Trunk:
Destination Address is the IP address or FQDN of the remote CUCM node (preferably Publisher or SIP-Enabled Subscriber).
Media Termination Point Required: Try enabling it for testing.
Security Profile: Ensure both ends use compatible non-TLS or TLS settings.
4- Double-check Route Pattern points to the correct SIP Trunk,
& There’s no overlapping pattern that could cause a routing conflict
5- Use Real-Time Monitoring Tool (RTMT) to trace the call & Look for any call routing rejections or digit manipulation issues.
04-03-2025 01:53 AM
Hi @William Pacheco
i suggest to do this checklist:
1- Make sure the CSS assigned to the SIP Trunk in Cluster A includes the Partition of the phones (or translation patterns) in Cluster B
2- Make sure the number dialed from Cluster A matches the expected dial plan format in Cluster B
3- Double-check the following on the SIP Trunk:
Destination Address is the IP address or FQDN of the remote CUCM node (preferably Publisher or SIP-Enabled Subscriber).
Media Termination Point Required: Try enabling it for testing.
Security Profile: Ensure both ends use compatible non-TLS or TLS settings.
4- Double-check Route Pattern points to the correct SIP Trunk,
& There’s no overlapping pattern that could cause a routing conflict
5- Use Real-Time Monitoring Tool (RTMT) to trace the call & Look for any call routing rejections or digit manipulation issues.
04-03-2025 03:39 AM
thanks @Mohammadreza Hadi
i checked CSS on both inter cluster trunk between two CUCM, and fix my problem..
issue was from wrong CSS selected..
04-03-2025 02:51 AM
You don’t mention if you have created any call routing configuration to make calls between your clusters. A inter cluster trunk in it self does not enable call routing between your clusters, you’d need route patterns for that.
04-03-2025 03:40 AM
thanks @Roger Kallberg for your attention
yes, i created router pattern between them,
but problem was from wrong CSS selected in trunk between two CUCM
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