No audio for MOH or ringing

My asterisk installation does not play MOH or ringtones during dialing.
Playing ordinary sound files works fine when using Playback.
I have full debug but the only message seen is:
"-- Started music on hold, class …"
Then just silence.

It is exactly the same environment as I have in other installations where it works fine.
Can this be dependent of service provider ?
Any ideas how to debug this ?


Do you get them if you first do a Playback? If so, this is an early media issue. Most service providers don’t like early media, because it allows a service to be provided before charging starts. Also, in some cases, Asterisk only forwards early media if you explicitly call Progress.

No, I don’t. I have allready answered an incoming call and done Playback which work fine.
Then I fire MOH (or ringing). But these just give silence and no error logging.

Found it!
dahdi was not started.

That should only be a problem on obsolete versions of Asterisk. All current ones allow timing sources other than dahdi.