RecieveFax failed when remote is traditional fax machine

Hi there,
I deployed asterisk + A102 sangoma with echo .
in extensions.conf, I write dialplan to recieveFax.
when I test it through windows fax service, the transmitted fax pages saved correctly.
but, when I use traditional fax machine I get error tranmission with result=49.
anyone have solution for this issue?

exten => Answer()
exten => Wait(6)
exten => RecieveFax(filename)

Is this spanDSP (app_fax), Free Fax for Asterisk, or paid Fax For Asterisk?


It’s spanDSP(app_fax)

You could try Free Fax for Asterisk: … terisk.php

and see if the results are different.

Fax For Asterisk is commercial and I were thought that asterisk already supports fax.