Ethernet-over-Coax (EoC) is a generic term for Ethernet transport systems that use coaxial cables to transport the Ethernet signal between two or more sites. EoC System is delivered by the master unit and slave device. EoC Master is one of key equipment of upgrading CATV system, which receives and mixes Ethernet signal and CATV signal and transmit the mixed RF signal to all the end users' cable interfaces via existing coaxial cable networks, and occupies low-frequency band outside the frequency range of CATV, well adapt to the diverse topologies of existing CATV networks. Then EoC Slave device will separate the data to the users' computer, and the CATV signal to TV. Fiber-Mart provides both EoC master units and slave devices for the whole EoC systems.