Baseband Ethernet on Thick Coaxial Cable (10BASE5)
The original Ethernet LAN defined in the 1980s was built from sections of thick, heavy 50-ohm coaxial cable. A LAN segment is either a single cable section or is made up of two or more sections joined by connectors (called barrel connectors because they are shaped like barrels). The segment at the top of Figure 6.1 is made up of two sections joined by a barrel connector.
Figure 6.1. A branching bus Ethernet.
A component called a terminator is attached to each end of a segment. Each 50-ohm terminator absorbs signals and prevents them from being reflected back into the cable. Coaxial cable ...