[Asterisk-Users] Asterisk Fax

[George Pajari]

Mr.  Rubinstein:

> I have read a lot about the thread of faxing support in Asterisk as  
> well as spanDSP. However, either I don't fully understand other  
> people's applications or may be what I'm trying to do is different  
> from what others are trying to do.

The fax support discussions you have been reading have revolved around 
having Asterisk behave like a fax machine, answer and decode the 
incoming fax call, and deliver the resulting received fax as an 
attachment to an email.

> I have a very simple setup. I have an asterisk server with a TE110P  
> connected to the PSTN via T1 PRI (Asterisk A). I have another  
> asterisk server with a TDM40B board with 4 FXS ports (Asterisk B)  
> where I have an actual physical fax machine connected to one of these  
> ports. These two machines are in two separate locations connected via  
> a point-to-point T1 circuit. What I wish to do is program a DID on  
> the T1 so that when the call comes into Asterisk A on that DID, it  
> will be routed via IAX2 to Asterisk B, which will in turn patch the  
> call through the FXS port where the fax is connected. Obviously, I  
> also wish to be able to send faxes in a similar opposite direction.
>
> Is this possible with Asterisk? Will it work?

Yes. Yes. And totally unrelated to spanDSP and other discussions related 
to turning Asterisk into a fax machine.

Apart from the relatively trivial task of configuring your two Asterisk 
boxes to route calls appropriately, the only two things you need to pay 
attention to are (a) ensuring you use g711 for the IAX2 link (using, or 
permitting, any other codecs will destroy the integrity of the channel 
as far as data/fax modulation is concerned), and (b) ensuring that your 
IAX2 traffic takes priority on the T1 circuit so that other large data 
transfers do not introduce so much jitter or packet loss as to render 
the VoIP traffic unusable.

-- 
George Pajari, netVOICE communications    604 484 VOIP (484 8647 x102)
Open Source VoIP/Telephony Specialists  1 877 NET VOIP (638 8647 x102)
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