OK i have a tdm400p with 4 fxo ports. the problem i am running into is that when i am on a sip phone (not a soft phone) and another call comes in i can hear a ringing. the person that i am talking with can also hear the ringing on thier end as well. any ideas what might be causing this because i need to resolve this.
sounds to me like you should try testing the POTS, and remove asterisk. unplug the lines from the TDM card, and plug in good old fashioned phones and see if the problem is still there. If so its the POTS lines, if not, try plugging one in, and see what happens. Do it in steps to isolate the problem, changing one thing at a time.