Yeah, I assum ed that when you can't hear the other person it's a downstream issue and if they can't hear you it's upstream. However, as I stated in monitoring the modem it showed no signs of any RF issues (ie good return, forward, no packet loss, no power adjustments or flaps). So that made me start thinking that maybe there are certain things with the cat5 wiring that may cause this issue (but I'm having a hard time swallowing that). I haven't swapped the modem yet either but I guess that's my next step. I would've done that to begin with but every fitting in the house was a full turn too loose so I figured that was the cause. I was wrong.