We have 2801 CME router. Also I connected a fax to this CME. But it gives communication error when sending fax and sometimes receiving. I tried with ATA and FXS ports but still the same problem. When I connect an analog phone to this line I can make calls and receive calls. Also when I connect directly analog line to fax (no cme) it works no problem. What can be the problem ? (Also I tried with two faxes) Can there be a software bug?
(C2801-SPSERVICESK9-M), Version 12.4(20)T1, RELEASE SOFTWARE (fc3)