Try tying your AC power and telephone cords in a knot as close to the router as possible. If that doesn't solve it, go to Radio Shack and get some chokes: part #'s 273-104 or 273-105.One or both of those solutions will usually do it. Also, keep your ...
Make sure your numbering type and plan are set correctly on the gateway configuration page in CallManager. They should be set to ISDN and North America for the US.
Actually you were right the first time. Cisco 800 series routers do NOT support VoIP. Cisco 802 and 804 routers have POTS ports to allow use of the ISDN line for voice, but it cannot use the ISDN line or POTS ports for VoIP calls.
Why not let your long distance carrier do the work?Most carriers will implement LD codes for little orno charge unless you need a huge number of them. Ifyou are not concerned with auditing employees calls,you can probably just get one code per depart...