Unable To Get Consistent Internet Connection On Cox Cable With Motorola SB6141

I started to get intermittent internet using Cox Cable, a Motorola SB6121, and an ASUS RT-N66U router. After buying a new router and swapping the SB6121 for an SB6141 I still had the problem. The internet would work OK for a while — sometimes 10 minutes, sometimes for a few hours — before giving up completely. The only way to revive the connection was to reboot the modem and the router.

I finally give in and called Cox who sent a technician and found the power levels to be out of range. He replaced a small attenuator that is connected between the modem and the Cox coax and everything worked fine.

He told me the Power TX levels for my area should be from 35-52 and RX level should be between -10 and 10.

Looking at the SB6141 I can now see what the levels should be under the Signal tab. That info can be accessed on the SB6141 by going to 192.168.100.1.

Click on the image below to see a larger version.