we recently upgraded a customer CUCM system from 6.1.2 to 9.1... it was a stepped upgrade, so in a lab environment we installed the customer version (6.1.2) and restored his data on my lab, then we stepped up to 6.1.4, then upgraded to 9.1.. then we took a backup of the cucm 9 version, installed ( for the customer and did a restore.. this worked perfect.
however, they had an intercluster trunk to another 6.1.4 CUCM.
so basically what exists now is two separate systems (9.1 and 6.1.4) , with a inter cluster trunk between them. the trunk is up, i can call both ways through it, but MOH and tranfer isnt working... MTP on both sides are checked..
Im not sure if this is a compatibilty issue between the two versions or if im missing something... can someone assit if possible..