What is inside a Cable Modem or Router A cable modem is a type of network bridge and modem that provides bi-directional data communication via radio frequency channels on a hybrid fibre-coaxial (HFC) and RFoG infrastructure. Cable modems are primarily used to deliver broadband Internet access in the form of cable Internet, taking advantage of the high bandwidth of a HFC and RFoG network. After unscrew the box I found there is two board for my cable router one is for wifi and another is the main board. Main board It usually depend on the router type and company choice whether they will use both in one board or they split up.. WiFi Board WiFi board It is about 150 mbps speed with Fully control features Main Board Its contain coaxial connector and two Rj45 connector and LED status light download file now