[Asterisk-Users] FAX over SIP

Ing. Angel Gomez Garcia
2003-09-03T23:18:32Z

Hello.

    Has someone been able to make work faxes over sip, i have one mp108
fxo and one mp108 fxs, my  setup is :

telco analog line -----> mp108fxo -----> Asterisk ------> mp108fxs
-------> fax machine

1) Asterisk detects the tone from the sending fax ( i am receiving ) but
looks for extension 'ff' not 'fax', ( at least that's what *
complaint,
invalid extension ff in context ).

2) I add 'ff' extension and dial to SIP/faxdev, Asterisk routes the call
to this extension but when the fax answers the call is dropped ( don't
have here the SIP debug output ) but seems that when * tries to make the
bridge the mp108 fxo sends a BYE.

3) I dialed in to * with a phone ( external line and internal extension
) and dial extension for the fax and i cann hear the fax, so the call is
not dropped, the bridge is established successfully.

4) If I pickup the call on the fax machine ( it has a phone set ) and
then pressed the 'start' button to start de fax receiver, then, the two
faxes talked to each other and the fax is received well.

    Seems that the problem is only when the fax answer automatically (
could be the tones the receiving fax plays ? ), the same problem happens
when i try to use hylafax to receive the fax.

    Any hints ?

    Thank's.