The router supplied with my Comcast Business service isn't the best piece of equipment, compared to a Soekris or PC Engines embedded device.
I've been having problems with my downstream, and I finally figured it out. I have 13 public ip addresses, and I'm only using a few at the moment. For some reason, when one of the unused ip addresses was the destination of a packet, there would be a packet storm and the latency would skyrocket from 5 milliseconds to 1000 or more. I ended up having the bandwidth shaper net4501 setup as a proxy arp in m0n0wall for the unused ip addresses. This fixed the latency issues!
