We are experiencing call drops after about 2-3 minutes on outbound calls. We have a global SME cluster (1 PUB, 6 SUBs) and 3 regional CUCM "leaf" clusters (1 PUB, 4 SUBs/cluster). We are running currently running CUCM 9.1.2.12900-11 and were told that CSCud64851 "CM does not send 200 OK due to glare before call is answered" is the cause.
Fix suggested was to upgrade SME only to 9.1.2 SU 5 using UCSInstall_UCOS_9.1.2.15900-7.sgn.iso
Has anyone else had this issue while running on 9.1.2.12900-11?
Would best practice be to upgrade all clusters to same version of CUCM?
Will having SME cluster and leaf clusters running different versions cause performance issues?
