One more thing and this is again only my opinion but based on my experience: If you have Comcast but are not using their rental modem,: You will still have major issues. Yes there are many modems that claim to work with Comcast. I bought and tried many. They worked OK (until I really pushed multiuser content or the band width I paid for ) Than the multi user system crashed and locked. With enough complaints Comcast came here and installed their same as modem for free and everything worked great. Two months later the rental bill showed up. So if you think it is OK to use a different modem than the Comcast rental modem, It is not true as Comcast is a dixk. Yes they will block your aftermarket modem (even an exact copy of theirs) and force you to pay that extra $10 a month to use their modem as this lets them monitor your every move.