Asterisk and Faxes over PRI


#1

Another post today, but this problem i much too hard…
For one of my customers i made an asterisk pbx, with a digium 4 pri card…
The system works well from many months, but sometimes it has problems to receive faxes, they arrive “corrupted”, for example 10 lines compressed in one!
What is, if exist :smile:, the “perfect configuration” to receive faxes over pri?
zapata.conf, zaptel.conf and so on! (the span 1 is connected to telco)
Bye!


#2

Typical echocancellation problem.

Try using the

faxdetect=both/incoming/outgoing
option in your zapata.conf.

This will route any faxcall to the “fax” extension (define it) and turns off echocancellation for this channel.


#3

Yes, right.
But in my system the faxes aren’t processed by Asterisk, but there’s a fax server windows 2003.
The call-fax arrive in the span 1 and then asterisk pass this call to a Siemens PBX (span 2) and finally arrive at fax server.
If i plug the PRI to the Siemens the faxes arrive well…

i have the echocancel set to 32, eche cancel when bridged off and echo training to 400…
I can use fax extension in my configuration?
For example:

exten => fax,1,(Zap/G2/numberoffaxserverSiemensSide)
exten => fax,2,Congestion
exten => fax,102,Congestion

It’s right?


#4

I didnt assumed you process faxes directly by asterisk.
Echocancellation is a problem with the very tones on the channel, not the processing of them, so yes:

Your example would cause a non-EC bridging, but please append “DIAL” to your first line finally :wink:

Oh, PS:
If you are tired of a W2003 Faxserver (for what reason ever) like i was:
A SMALL linux machine with Hylafax and soft IAX modems on it works like a charme !

The mainreason for me saying goodbye to my W2K Faxserver was:
Licence was to renew anyway
Some VERY important functions missing (gateways and Tiff/PDF stuff)
I dont wanted to have another (HCF) ISDN card to connect only this server

The Hylifax IAX softmodems are using IAX protocol, are opensource and only need a network, yay


#5

[quote=“RichardHH”]I didnt assumed you process faxes directly by asterisk.
Echocancellation is a problem with the very tones on the channel, not the processing of them, so yes:

Your example would cause a non-EC bridging, but please append “DIAL” to your first line finally :wink:

Oh, PS:
If you are tired of a W2003 Faxserver (for what reason ever) like i was:
A SMALL linux machine with Hylafax and soft IAX modems on it works like a charme ![/quote]

OoooPs! Dial missed! :smile:
What means non-EC bridging? (sorry but i’m a beginner!)
For the fax server you have full reason, but i’m not sysadmin of that area!


#6

Hi,

with “NON-EC Bridging” i meant a bridged call without echo-cancellation.