StopMusicOnHold() — Stops music on hold
Ends playing music on hold on a channel. If music on hold was not already playing, has no effect.
; transfer telemarketers to this extension to keep them busy
exten => 123,1,Answer()
exten => 123,2,Playback(tt-allbusy)
exten => 123,3,StartMusicOnHold(default)
exten => 123,4,Wait(600)
exten => 123,5,StopMusicOnHold()