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.