Below is a link to a list of modems that are compatible with Optimum. Depending on the speed you have you will need to get a modem that can accommodate that speed.
A modem has channels that represent the speed it can handle. It's displayed as download channels x upload channels, so a 16x8 modem means it has 16 download channels and 8 upload channels.
It's not recommended to get anything lower than 16X8 since speeds are only going up in the future.
Chart showing the channels needed to support the Optimum speed
- Optimum 100, 8x4 or higher
- Optimum 200, 16x8 or higher
- Optimum 400, 24x8 or higher
There are many modems available on Craigslist's and eBay as well, there is no need to buy a new one as long as it's compatible.
https://pickmymodem.com/approved-modems-for-optimum-cablevision-internet-service/Once you have the modem you can call Optimum tech support and ask them to provision a new modem and give them the MAC id located a the modem. They will also send you a prepaid FedEx label to return their modem and the price will be reflected on your next bill. You just saved $10 - $10.89 a month in fees.