[asterisk-dev] MOH not working on custom channel driver

[Earle Clubb]

I'm writing a channel driver and I'm having trouble getting MOH to play 
on my device.  Audio works fine both ways in calls with SIP phones, but 
when a SIP phone puts my device on hold, or if I call MusicOnHold() from 
the dialplan, no music plays out of my device.  I am able to play a file 
using Playback().  In my indicate() function, on receiving 
AST_CONTROL_HOLD, I call ast_moh_start(ast, data, pvt->mohinterpret).  
As soon as I make that function call, Asterisk stops sending audio 
frames to my driver.  When I call ast_moh_stop(ast), I receive normal 
audio frames again.  This is all I'm doing in my driver regarding MOH 
(except for setting mohinterpret and mohsuggest).  What have I missed?

Thanks,
Earle