Atlas 550 with a traditional PRI connection to PSTN(no SIP)
4 fxs\analog cards in atlas allowing for 24 "Pots" lines
Connect any type fax machine to one fax port on Atlas
When faxing to another fax machine thru the Atlas the baud rate drops to 9600 which makes for real slow faxing, often the other end fax hangs up due to the slow speed
Are there any settings that would cause this slow down in baud rate in the Atlas 550?
Check for errors or timing slips on the T1 to the PRI. Also you might need to tweak the impedance settings on the FXS port(s) to match the fax machine. Check also for bad wiring on the analog side. Do you hear any artifacts if you place a voice call on the line such as hum, static or a periodic ticking?