[Asterisk-Users] Faxing..not 100%

[Lee Howard]

On 2004.12.07 10:06 Matthew Boehm wrote:
> Here is the setup:
> 
> POTS -> PRI -> Asterisk -> ATA (Fax)
> 
> The ATA is set to only 711. Asterisk's sip.conf sets this device to
> only
> 711. Yet, faxing works less than 50% of the time.

I have a couple of different fax arrangements with Asterisk.

   POTS -> Asterisk (X100P) -> ATA -> Fax Modem (HylaFAX)

Probably the *only* reason I can get anything through this arrangement 
reliably is due to the Class 1 ECM support of HylaFAX.  I see lots and 
lots of ECM frame data errors, and the sender has to resend them, and 
the faxes take longer than they should.  There are still often problems 
due to a lack of synchronicity between the sender and the receiver, but 
most of the time everything works out.

   POTS -> PRI -> Asterisk (TE405P) -> Patton T1 Fax Card (HylaFAX)

This is a nearly flawless arrangement when receiving.  I don't have any 
problems with it, at least to any extent that I've noticed yet.

The only real difference that I can see in this scenario is that there 
is some A->D/D->A conversion that is probably going on probably both on 
the ATA and on Asterisk, and somewhere in that process it's being done 
badly.

> Will going thru a router that supports T.38 help? I don't see how
> since
> Asterisk doesn't talk T.38.

T.38 is supposed to be the end-all happy solution to FoIP, but Asterisk 
does not yet support T.38.

Lee.