[geeks] Q: Cable modem failing?

[Andrew Jones]

On 12/27/2012 11:56 AM, Lionel Peterson wrote:
> Hello all,
>
> I have a plain, old, Motorola Cable modem (SB5101, Docsis 2.0), and it seems
> to have started having problems.
>
> This is a 7 year-old device, and what I am seeing is that Internet speeds will
> slowly degrade to the point it is unusable, then rebooting the cable modem
> sets things right for 24-48 hours it seems.
>

I had similar problems when my signal quality had been degraded by rain 
damage to cabling. When the signal was good, the modem would correctly 
negotiate a high speed, but when the signal was bad, it would negotiate 
down and stay there.  When rebooted during a "good" spell, it would 
briefly be faster.

ISTR that all Motorola modems have a user-reachable diagnostic page on 
192.168.something, and that will show you the SNR at any given time.