I've done all the normal resetting of my cable modem, router and other equipment in my home (firewall, proxy server, etc..) and my service is still slow much of this morning despite paying for their highest tier Internet service.
As I use OpenDNS anyway, that hasn't helped. There's something else going on around here.
well, you can always call Comcast - they’ve actually been pretty responsive when I’ve had problems, either individual or neighborhood node issues. Aside from rotten cottenwood trees and auto wrecks taking down their lines, we do occasionally also have neighborhood node issues as well as individual problems. I lease my modem from Comcast and they’re replaced it multiple times over the last 15 years - average lifetime of these SOHO boxes is generally 18 months.