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fax2email explanation PDF Print E-mail
Tuesday, 04 May 2010 23:51

Hi Guys,

We got some questions related with fax2email so here some clarifications.

In Switchfin we have added spandsp library and this opens area for new applications related with fax receiving/sending.

 

It is often convenient instead of scanning and emailing given paper to fax it instead.
In addition many people still prefer the old way and send the information using FAX machine.

The basic setup is like this. (Note that you can use SIP channel to connect with the FAX machine but it is
outside of the scope of this message)

(FAX machine) -->FXS-->[Switchfin PBX] --> email with attachment tiff image from the FAX machine -->

The email is sent by your company/home mail server or you can use any free SMTP server available.
Currently the fax2email feature is not integrated in the Switchfin GUI so you need to adjust the Asterisk config files manually.
We will get this feature integrated pretty soon.
It is actually simple. Just put your FXS/SIP client in the context similar like the following one

[fax]
exten => 300,1,Answer()
exten => 300,2,Set(FAX_FORCE_V29=1)
exten => 300,3,RXFax(test1.tif,log=/var/log/rxfax.log)
exten => 300,4,System(/bin/mailfile.sh test1.tif This e-mail address is being protected from spambots. You need JavaScript enabled to view it )
exten => 300,5,Hangup()

exten => 301,1,Answer()
exten => 301,2,Set(FAX_FORCE_V29=1)
exten => 301,3,RXFax(test2.tif,log=/var/log/rxfax.log)
exten => 301,4,System(/bin/mailfile.sh test2.tif This e-mail address is being protected from spambots. You need JavaScript enabled to view it )
exten => 301,5,Hangup()
...

During our tests we find out that the different FAX machines has different signal strength and it seems the level control in spandsp is not perfect.
To get stable FAX transfer you may need to adjust the rxgain/txgain in /etc/asterisk/chan_dahdi.conf.

The rocket stable results we got with:

rxgain=3.0
txgain=3.0