My customer has a 2621xm router with an NM-HDA adapter. I can call the phone attached to the fxs port but if I try to dial out or dial an IP phone from the the phone attached to the fxs port It does not seem to collect digits I get a constant dial tone. They have CCM 3.3 and the router is configured as an MGCP gateway. Im suspecting either code of defective FXS port. I have also tried using the other 3 FXS ports and get the same scenario.