Yes, if you understand and accept the risks involved and would still like to use a third-party modem, you may do so. You will need to get support from the modem's manufacturer. Though there are some similarities across brands, it's best to get instructions specific for your particular model's features and settings. Go to the manufacturer website (for example, Netgear, Motorola, D-Link, etc.) and search for the specific model name/number to find any user guides or help articles offered by that company, as well as customer support contact information.