Thank you all for your replies,   I noticed that this issue is  not always happening (its intermittent) today it works normally (I didn't do any changes) !!   @HARIS_HUSSAIN I will try to see if the packets are incrementing when I get the issue again and tell you the result.   ... View more

@Dennis Mink wrote: So  phone on cluster a rings phone on cluster b. Called phone picks up and after that dead air?   Has this worked previously? If you have signalling but no audio then its most likely caused by routing. So verifyif you can ping between phones. Thank you for your reply Dennis,   It is exactly as you described, but from phones on cluster B when I call a phone on cluster A everything works fine (the problem is just in one direction from A to B only).   YES! It worked perviously.   I have the two phones in two diffrent Voice VLANs I will check routing between them and tell you.   ... View more

@Graham Old wrote: When you put a call on hold do you get the default MoH or do you get silence or do you get the beeps every few seconds. Somethings to check. If you put a call on hold using your phone it is your MoH selection that is played to the other end. After changing MoH you must reset the device to pick up the changes. Some companies like to turn off MoH because if they are on a conference call and if they put the call on hold they flood the conference bridge with Music. On UCM go to System/Service Parameters/Select the Pub/Cisco Call Manager and check the Default MOH Audio Sources are set to a valid stream number. Graham Hi Graham,   - I get silence when I put calls on hold. - Nothing happened even when I restarted the devices. - Can't find the stream number !   ... View more

@tgaur wrote: hi,   is the MOH working for internal calls.   check if the MOH servers are registered.   check if the default audio files are working.   check the custom file is upto recommended format :   These are some examples of a valid input audio source files: • 16-bit PCM .wav file • Stereo or mono • Sample rates of 48 kHz, 44.1 kHz, 32 kHz, 16 kHz, or 8 kHz   if the internal calls working fine, issue is only with external enable the duplex streaming on CUCM    if everything is fine open the TAC case.   Thank you for your reply, I tested with internal calls and it didn't work. The MOH servers are registered, I will check the audio file specefications like you mentioned and will tell you. Thank you again. Regards, Hamza. ... View more