Ethernet over Coax Cabling

Ethernet over Coax Cabling

The use of coax cable for LANs is virtually nonexistent. One might run into it in an old abandoned building. Ethernet's eventual support of twisted pair cabling in a star topology virtually ended the use of coaxial cabling for Ethernet. Keep in mind that coax cable was not cheap either. Two major types of coax were used: thinnet (also called cheapernet) and thicknet. Thinnet uses 50 ohm coaxi cable (RG-58 A/U) with a maximum length of 185 meters when used for Ethernet. This cable is thinner and more flexible than thicknet, which is also 50 ohm coax cable. It is packaged and insulated differently than thinnet. It requires a specialized tool, a vampire tap, to pierce into and has a maximum length of 500 meters for Ethernet. The vampire tap was used to pierce the outer shielding of the cable, creating an electrical connection between the device and the shared media. Traditionally, thicknet was used as a backbone technology because of its additional shielding. Both thinnet and thicknet are virtually extinct in production networks today.