New cable modem sucks more than comcast one?

[cryptonomicon]

OK, here's the deal. My old roomate had all the networking equip, and he just moved out so I have a new motorola sb5100 cable modem which is supposed to be a top of the line cable modem. However this thing seems to get crappy latencies after a day or two of being on with continuous use, and the old COX one that come from comcast never used to die like that, even though it was just a white boxxed POS. I think I only cycled the COX one like twice in 3 months, and Ive cycled this new one like 5 times in a few weeks.

When I power cycle the modem (and subsequently everything down the line-- just a 4 port linksys router) and get it back up again, the problem seems to dissapear for a while.

Now it could be a couple of things going wrong, not just the cable modem's "cache" as i'm told. Such as... comcast could be sporadically lagging, or maybe i just needed to renew my IP from the DCHP server.. or who knows. But I don't think it's comcast :\ because they have been doing a pretty good job and I have very very little downtime. So is it the modem? Can someone give me some insight?

Has anyone had a "bad" modem that degraded over time... is this common? :X

 

[cryptonomicon]

Ok, I think I may see a problem. I tried tracerouting a few servers I know and there is a major latency problem on comcast's side of the line. There is 1 hop that adds about 120ms latency and the previous hops are only 9,10,and 10, respectively. The hops after the 120ms jump only grow by less than 10ms each, so we know this is a problematic hop. Also, the DNS name of the hop after the laggy one is "... sffca.ip.att.net" and I know I ping less than 50 normally to anything in northern california, so this is obviously a network outtage.

I still don't trust the modem though >.<