On Unity, I'd suggest you enable these traces in the Unity Diagnostic Tool (UDT):
mAcro traces for Conversation and Skinny TSP.
You should set up detailed traces on CM as well.
When the problem recurs, then on Unity gather the AvCsMgr and svchost traces from UDT. The svchost traces will provide the Skinny traces that are much like the CM traces. You can then compare the digits input at the phone or transmitted by the gateway to what Unity is receiving.
If the digit sent is the same as the digit received, then the issue can be further troubleshot in the AvCsMgr traces.
I'm not able to access my old voice mail messages all of a sudden. The recording says something like 'the message is currently not available'. This has never happened before in all the years I have been using this system. I have t...