TP-Link makes inexpensive yet nice Cable Modems, which can save you from those exorbitant Rental Fees charged by your predatory Cable Internet Provider.
We've been using a TP-LINK TC-7610 for a few months, here's a Python script we put together to reboot it. You can easily use it to reboot your cable modem upon loosing your Cable internet.
reboot_tc7610.py
Let us know here if you have feedback or comments.