Comcast Cable Modem Lag Problem

[jldavid]

My setup:

Comcast cable -> Motorola SB5120 Modem -> Linksys WRT54G Router

The problem: I get random network delays (lag) going to/from the internet. This affects games, browsers and all applications that depend upon an uninterrupted data stream from a remote server (e.g. real-time financial programs).

What I've done so far: I've tried removing my router from the stream without success. I believe the problem is with the cable modem because when I do a tracert to the comcast DNS server without the router present I get

C:\>tracert 68.87.72.130

Tracing route to chic-cns.area4.il.chicago.comcast.net [68.87.72.130]
over a maximum of 30 hops:

1 * * * Request timed out.
2 6 ms * 7 ms ge-1-42-ur01.wchicago.il.chicago.comcast.net [68.86.119.45]
3 8 ms 9 ms 9 ms te-1-3-ar01.elmhurst.il.chicago.comcast.net [68.87.230.213]
4 8 ms 9 ms * te-9-3-ur04.area4.il.chicago.comcast.net [68.87.230.214]
5 10 ms 9 ms 11 ms chic-cns.area4.il.chicago.comcast.net [68.87.72.130]

The first hop is my cable modem. The time out happens EVERY time I do a tracert. If I do the same thing with the router in the stream, I get the first hop like this:

1 1 ms 1 ms 1 ms 192.168.1.1

with the second hop (my modem) ALWAYS timing out as above (192.168.1.1 is the address of my router). So it does not appear that the router is the problem.

Now, when I look at the logs for my cable modem I see no entries when the problems occur. It is as if packets are being dropped just for the heck of it.

What do you experts recommend? I'm currently renting the modem from Comcast so I'm sure I could get another one (assuming I could convince the "techies" on the other end). If I purchase my own modem, what would you all recommend? Is it possible that the problem is further downstream?

Thanks.