My Experience
Since all the issues started with the gaming on two machines, it's gotten even worse. I've had my ping times go up in BF1942 until I lagged out, with only me even in the house. My roommate and his brother get terrible lag in Unreal Tournament that goes up and down, on both our connection and his brother's (both cable), even with only one person playing.
Now in the past few days, I've started losing connections without the ping times even going up. I can play for an hour to an hour and a half, then suddenly get "connection problems" and then I'm disconnected, during which the ping times still show at the 46ms or whatever that they were the whole time (I assume that it just shows what it was when the last packet came back, and now all packets have stopped). When it finally disconnects, I also discover that my IRC session that I keep connected while I'm playing has disconnected too. AIM also sometimes loses connection but seems to have a longer period to time out.
None of this happened until about 3 weeks ago. Mediaone was a great cable company, we never had any issues at all. When AT&T took over, we started having losses of service every few weeks. Then after they changed the name and spun it off as a separate company, AT&T Broadband Inc., the loss of cable sync happened on a weekly basis, sometimes for hours at a time. We never even bothered calling tech support because we knew it'd come back up eventually, and they wouldn't have any knowledge of widespread problems and would just schedule a tech to come out.
Now that Comcast has taken over, it's started all this garbage. It is not a hardware or network problem on the customer end. Everything was working fine until Comcast took over the network. And they won't even discuss problems until you connect only one machine to the cable modem, in which case the problem isn't even reproducible.
I personally think they've made changes to limit people's usage severely, because they think we shouldn't be allowed to make full usage of the lines all the time. They've either put more people onto each headend router so they have fewer routers and more overselling of bandwidth, or they've put in a packet rate limit of some sort, or even something to sniff the packets and depreference certain types (so they get delayed until higher priority traffic has passed). It's certainly not a simple bandwidth cap lower than before, because I can still download and upload just as fast as before. Even downloading at 100KBps or higher while one person is gaming doesn't cause them to lag out, only two people gaming (which uses little bandwidth comparatively).
