Just over 12 months ago, we migrated all our telephony users onto a stable v9 call manager/uccx platform from various versions and so far has been running smoothly.
Recently 2 of our smaller sites, who use call transfer on a regular basis started to experience issues whereby intermittently they would see calls being dropped/disconnected when attempting to perform an internal transfer. Some have experienced it when they dial the internal extension, and other transfer the call successfully to the new transferred number, but when they try to connect the original call it disconnects the original caller.
We are using SIP cubes for all our sites, and transfers are intersite, so using the same route pattern/partition.
I'm lost as to what to look for, as this is so intermittent.
Can someone help?
Thanks,
Natalia