Yes, it is possible to use your own modem with Optimum's internet service, provided that the modem is compatible with their network. Optimum typically requires that any third-party modem support specific technologies and standards, such as DOCSIS 3.0 or DOCSIS 3.1, for optimal performance. It is advisable to check the list of approved modems available on Optimum's website to ensure your device is compatible. Additionally, it is important to remember that if you choose to use your own modem, you may forfeit certain support services that Optimum offers for their provided equipment. Therefore, if you encounter any issues, you may need to troubleshoot the device independently. For the most accurate and updated information regarding compatible modems, visiting Optimum's official website can be quite helpful.