GOfax.IP is a HylaFAX backend/connector providing Fax over IP support for HylaFAX using FreeSWITCH and SpanDSP through FreeSWITCH’s mod_spandsp.

In contrast to solutions like t38modem, iaxmodem and mod_spandsp’s softmodem feature, GOfax.IP does not emulate fax modem devices but replaces HylaFAX’s faxgetty and faxsend processes to communicate directly with FreeSWITCH using FreeSWITCH’s Event Socket interface.

GOfax.IP is designed to provide a standalone fax server together with HylaFAX and a minimal FreeSWITCH setup; the necessary FreeSWITCH configuration is provided.


  • SIP connectivity to PBXes, Media Gateways/SBCs and SIP Providers with or without registration
  • Failover using multiple gateways
  • Support for Fax over IP using T.38 and/or T.30 audio over G.711
  • Native SIP endpoint, no modem emulation
  • Support for an arbitrary number of lines (depending on the used hardware)
  • Extensive logging and reporting: Writing xferfaxlog for sent/received faxes; Writing session log files for all sent/received faxes
  • Support for modem status reporting/querying using HylaFAX native tools and clients: faxstat etc.
  • Call screening using HylaFAX’ DynamicConfig


OpenRheinRuhr, 2014

Chemnitzer Linux Tage, 2015


Looking for a new feature? Found a bug? Or just want to say thank you for GOfax.IP?

Don’t hesitate to get in touch with us on Github via Mail or just give us a call!

heterohyrax brucei

Our little friend

Ever wondered, who is our little likeable friend? It’s a Hyrax, also called dassie and in German Klippschliefer. A little well-furred rabbit-like animal which lives in Africa. The interesting fact about these animals, they communicate only with seven different types of sounds…Just like fax. :-)