Does anyone have a cure for echo on a docsis phone system? I use Arris TM402Ps, a CMTS 1500, Asterisk and a VoIP provider that is the same as my T1 provider so the network is fine. The upstream SNR is 34.9db. I have this old lady that says she hears her own voice. Believe me, I'm not ruling out mental illness either. Could it be the phone?