We are having two Call manager clusters. Suppose Phone 1 and Phone 2 are connected to Cluster 1 and Phone 3 and Phone 4 are connected Cluster 2.
When Phone 1 calls Phone 3 in Cluster2, and try to take Phone 2 in conference, Phone 3 in Cluster2 will automatically get disconnected. So we are not able to make conference calls.
But when Phone 3 calls Phone 1 in Cluster1 and take Phone2 also in Conference, it is working. ie it is working when Phone 3 initiates the conference. So it's like one way the conference happens.
Within both the cluster, Phones are able to participate in multi-party conference without any problem.
Can anyone tell why this happens?
Normally check the region configured between CFB and ICT.
Make a call between cluster and press twice the i button, you will see which codec they r using.
Then check which type of CFB you are using.
If you are selecting a SW CFB it only supports G711. Hence you will need a Transcoder.
Or change ICT communication to G711 which will affect BW usage across the WAN if theres a WAN involved.
Let us know
Nice thinking on this one! 5 points your great explanation as well :)