[Asterisk-Dev] Sending ISDN q.931 messages to Zap span?

[Andrew Kohlsmith]

I tried #asterisk-dev but everyone there is lurking or has me on /ignore.  :-)

I'm trying to send ISDN MWI indication to a PRI on a Zap span.  From what I 
gather from the CAPI documentation is that I send a FACILITY_REQUEST message 
with parameter set to 0x0003 and function 0x0013 (MWI Activate), filling in 
the supplimentary structure to indicate number of messages, message status, 
destination facility number, source facility, etc., etc.

Where I'm getting tripped up is in how to send this information over a PRI.  
What is the most straightforward or perhaps more accurately, the most 
flexible way of sending an arbitrary q.931 message over a Zap span?  

the zapata.conf mailbox settings are only attached to individual channels, and 
since I can't assign mailbox settings to the D channel that's out.  I was 
thinking perhaps something in the dialplan (perhaps a q931()) application) 
but perhaps wedging this into zapata.conf is better in the long run, at least 
for voicemail notification.

Can anyone assist me in getting started?

-A.