You won't find any router that takes coax, that portion is handled by a DOCSIS modem. In your case, you're unlucky enough to have been given a combined modem/ro

You won't find any router that takes coax, that portion is handled by a DOCSIS modem. In your case, you're unlucky enough to have been given a combined modem/router by your ISP. You have 2 options to improve performance - 1. Use a third party DOCSIS modem, if allowed by your ISP, along with a seperate, dedicated router. 2. Put the modem/router abomination into gateway mode, and get yourself a seperate router. If the modem does not have a gateway mode, you can often use PPPoE to bypass the modems routing function. This often resolves the connectivity issues introduced by these devices.