[Asterisk-Users] Limit fax tx speed of 'dumb' faxes??

[Remco Barende]

Hi!

Still trying to get fax to work in a reliable manner.

I have some dumb fax machines that do not have a setting to limit tx/rx 
speeds. For some reason when training they often think the line is good 
enough for 14k4 or higher after which the fax will fail.

Is there any other way of forcing the faxes to lower their speeds?

Would it be possible to monitor certain extensions for the sound pattern 
a fax machine generates during training to try 14k4 or higher and maybe 
jam the line or mute the audio for a moment? That way the fax will think 
14k4 failed and would switch to 9k6.

I'm looking to connect some fax servers (for various reasons spandsp is 
not an option) for incoming / outgoing faxes but even on recent modems 
like the MultiTech MT5634ZPX (PCI) it's not possible to cap the speed 
AFAIK.

Any hints greatly appreciated!