I receive about 1500 faxes a month with FreeSWITCH/SpanDSP and Flowroute.  I send about 100 or so, so not nearly as many in that direction.  Sent faxes almost always work fine short of noanswer, voice answer, etc.

 

For received faxes I get a lot more failures then I would like however, close to 15%.  Usually by the 3rd try most faxes make it through though.   I've been told (here) that this is absolutely horrible and any half-decent system would perform better but I've yet to be told what a half-decent system is or some "best practices".   I've fiddled with many settings and I seem to get the best overall success with the below settings (over the defaults).  I've gone back and forth with the v17 being disabled and it seems it works better with some fax machines having it one way and with other machines it's better the other way.  I'm working on making my lua scripts adjust the settings on-the-fly and remember what works for each CID or DID.

 

fax_disable_v17 = true

fax_enable_t38 = true

fax_enable_t38_request = true

fax_verbose = true

ignore_early_media = true

 

I've wrote a couple of small LUA scripts to use with FreeSWITCH to help manage faxing.  They allow you to configure DID to Email routes, set default fax settings and fax settings per DID or CID, view some basic stats, and a few other things all from the fs_cli console.  It stores everything in a sqlite3 database.  It's pretty rough around the edges still, but maybe it could help some.  The receive fax script has a bit of code that tries to figure out if a caller is a voice caller but I don't think it's entirely accurate but it does seem to work decently.

 

 

 

 

 

------ Original Message ------

From: "Markus Lindenberg" <markus.lindenberg@gmail.com>

To: "FreeSWITCH Users Help" <freeswitch-users@lists.freeswitch.org>

Sent: 7/11/2014 7:29:24 AM

Subject: Re: [Freeswitch-users] [OL]Re: best way to receive FAXs

 

On Thu, Jul 10, 2014 at 6:39 PM, Steven Schoch <schoch+freeswitch.org@xwin32.com> wrote:

I don't really want to "play" with T.38 faxing, I just want to receive faxes without a POTS line. Doesn't anyone do that?

Hi Steven, 

yes, I'm doing that, a lot. :)

Try to disable T.38 first and send a fax that way. If it works, try again with T.38. Have a look at spandsp's output on fs_cli, there's usually something useful if negotiation fails. You can also enable verbose output for mod_spandsp, that'll give very detailed logging output but can be useful as well. Maybe it's some problem with the T.38 re-invite, so maybe try a T.38 fax to/from your provider with siptrace enabled.

Best regards, Markus