[Asterisk-Dev] Voicetronix driver for V6PCI/V12PCI - first draft

[Mark Spencer]

>   Please find attached a first shot at a driver for the Voicetronix
> OpenSwitch hardware. It does work (ish).  After paying $900-odd for it
> I figured I might try to make it work with Asterisk (could never get
> enough documentation on Bayonne!)

There has been a great deal of interest in such a driver.  Please contact
me off-list for the disclaimer forms if you wish for your driver to be
placed in Asterisk's source tree.

>   I have problems with the audio quality, and since am new to Asterisk,
> I could really do with some input. First is that because the
> voicetronix api does not provide a nice way for one to emulate a file
> descriptor per channel (for asterisk to monitor for exceptions and
> data-ready), I had to use the monitor thread to generate data-ready on
> a pipe to force asterisk to keep trying to read from the channels if I
> wanted any audio recording.  In addition, I can't figure out a way to
> generate exceptions for asterisk, in order to pass hangup and such.

I would follow the chan_iax or chan_iax2 model.  Asterisk has mechanisms
designed specifically for this sort of scenario.  Basically, have your
monitor thread watch for data on all the channels, then call
ast_queue_frame() to queue your audio and control frames.  Be sure you
call ast_channel_alloc(1) so that it has a pipe.

Mark