RCA DCM425 Cable Modem

Instead of leasing a cable modem, why don't you just buy one for your residential Comcast cable? You could send $20 shipped and make your money back within 6 months. After that, you are starting to make money because you don't have to pay the cable company for leasing the modem. The modem is very straight forward. It has a connector for power and another connector for coaxial cable in the back. Some models have internet on/off in the front but not all do. Once you have connected the modem properly, you just call your cable company and have them "provision" the cable modem for your account. Provisioning just means that the cable company registers the MAC address of the cable modem (sort of like a serial number for network devices). Once you're done you are good to go.

I've used the cable modem for every day for internet and its been very reliable.