I have a customer that I am attempting to install a spa2200 ATA behind the Mikrotik RB750 that will be used for sending/receiving faxes. The ATA is configured to use T.38. With the mikrotik out of the picture everything works just fine. Once the mikrotik is installed the ATA will receive faxes but will never send a fax. The fax machine always says "Poor Line Condition" and I have tried multiple fax machines. I can simply remove the Mikrotik and it starts working.

Any ideas?

Thanks,

Charley Morgan