TDM400 FXS extensions crosstalk with fax machines

[phinphan]

My PBXIAF 1.4 system has a Digium TDM400 board with 2fxo and 2fxs. The 2 fxs are connected to two brother fax machines. When I dial a remote fax from either one the other will answer. Sometimes when I send a fax from one machine, the office line will ring as if an incoming call is coming in but it is from the fax machine. Does anyone have any idea what could be causing this? Is the signal from the fxs too strong or too weak, gain too high? Are my brother fax machines at fault. Dialing out on the pstn lines does not exhibit this behavior, only the fax machines through the fxs/fxo combo. I recently installed avantfax/hylafax and I can fax out from the server over the fxo lines without fail. Which leads me to either the fxs modules or the fax machines. But how to test?

I have no idea.

 

[tshif]

Well - I don't know if it would affect cross talk - but I do know its important to go through a tuning process to adjust the gain on your digium boards.

To everyone using the Joe Roper HylaFax/Avantfax script that I wrote about in another thread - you should read and follow these procedures to tune your gain factors. We have seem improvements from a 75% success rate to over 98% success on first attempts since tuning the gains as described.

 

[phinphan]

I will give that a try. I don't even know if cross-talk is the right term, I just dial out on machine 1 and machine 2 picks up the line as if I had dialed that extension or the phone number.