I purchased this modem to use on the Comcast XFinity network, as an upgrade to an older Motorola modem that no longer supports my current subscription speed. I hooked the modem up to the network, precisely as prescribed in the installation manual, but could not get the uplink channel locked in so that I could connect to the activation site. I power-cycled the modem multiple times, but still no success so I called XFinity to see if they could establish the channel from their side. They tried sending signals to the modem for over an hour, but finally gave up. There was no problem with the network connection since we were quickly able to re-connect my older modem. I tried calling Netgear's tech support line a couple of times... the first time waiting 75 min on-hold while I only moved from position "nine" in the queue to number "five". I tried again mid-day, and found myself waiting without movement at number "15" in the queue. I finally gave up and am returning the defective modem.