asterisk/doc/README.h323

The Asterisk PBX supports H.323 via two totally separate 
channel drivers.

You can find more information Asterisk's native H.323 
support in /path/to/asterisk/channels/h323/README or 
you can download a third party driver at
http://www.inaccessnetworks.com/projects/asterisk-oh323

Asterisk's native H.323 is supported and maintained by
Jeremy McNamara (JerJer in irc). Support for the third 
party H.323 driver is supplied by inAccessNetworks. 

If you have trouble with either driver you should direct
your debug and comments to the appropriate party, making
sure to be specific in exactly which H.323 driver you are
running.

Please, read all supplied documentation before contacting 
either party for support. Many issues can be quickly
resolved by simply following the instructions that are 
provided.