Grandstream GXW4104, Asterisk and FAX

Hi all,

I’m running Asterisk 1.6 and used to use a digium POTS card and dahdi drivers for my call handling… The system was able able detect a FAX call and route it to hylafax via the IAXModem. This all worked just fine. I then moved over to using a grandsteam GXW4104 to handle the inbound calls, voice calls are just fine, however it seems that no matter what I try I’m not able to make the system detect a FAX call and route it to the FAX extensions and onto hylafax.

Has anyone else managed to make this work? Are there some hidden SIP parameters which enable FAX detection like there are for dahdi?

Any help would be great.


I think you have to enable some t38 options in sip.conf files.