i have two callmanagers and we are using h.323 gateways with gatekeeper.
the calls from one cisco phone registered to callmanager1 to outside mobile phone doesn't play any announcement when the mobile is not available.
while if i use the phone registered to other callmanager2 then it plays.
so what i interpret is that there are some settings in the callmanager itself.
i think that the phone tries to play some message but it gets disconnected immediately.
i have found one link also from cisco.
but this one tells about changes in gateway. which is fine at my side.
your help will be appreciated.