[Asterisk-Users] T.38 "pass-thru"

[Tracy R Reed]

On Mon, Sep 06, 2004 at 01:34:50PM +0300, Elman Efendiyev spake thusly:
> Jusc couldn'n transmit faxes trouth asterisk. It just hangs up when
> starting a fax transfer
> If U will do some experiments with it I would be happy to hear any
> reslts/info

I have given this some more thought. Fax Protocol it T.30. Fax over VOIP
is T.38. If you send a T.38 stream out a Zap channel the other end of the
modem which expects straight T.30 will be getting T.38 also which will
mess everything up. I'm still a bit unclear on exactly what T.38 provides
and why you can't just do straight T.30 over VOIP (I'm pretty sure you can
plug a fax machine into an ATA and do fax over VOIP with g.711) but in
order to make T.38 out a Zap channel work Asterisk is going to have to
understand T.38 and strip the T.38 off leaving only T.30 to go out the Zap
channel.

-- 
Tracy Reed                     The attachment is a digital signature.
http://copilotconsulting.com   More info: http://copilotconsulting.com/sig
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