Receiving and sending a fax in FreeSWITCH is excruciatingly simple, consisting of two applications:
rxfax(/path/where/to/write/TIFF)txfax(/path/where/to/read/TIFF)
That's it. Isn't that a beauty? Thanks to the world-class work of Steve Underwood, the recognized Godfather of Digital Signal Processing, SpanDSP library is integrated into FreeSWITCH and, amid many other goodies, provides complete T30 and T38 fax communication support.
Note
FreeSWITCH sends and receives TIFF files. You must do all the necessary conversions (to/from PDF, and so on).
All the finer details of fax communication are determined by a mod_spandsp configuration file (overridable runtime for each application invocation) and by information contained in the TIFF file itself (for example, resolution, size, color or b/w, and so on). Again, mod_spandsp configuration (overridable) determines if and how a T38 call upgrade will be attempted, and T38 terminal or gateway behavior to/from T30 and TDM (PSTN).
