A type of standard for implementing Ethernet networks. 10Base5 is sometimes referred to as thicknet because it uses thick coaxial cabling for connecting stations to form a network. Another name for 10Base5 is Standard Ethernet because it was the first type of Ethernet to be implemented. 10Base5 supports a maximum bandwidth of 10 Mbps, but in actual networks, the presence of collisions reduces this to more like 4 to 6 Mbps. 10Base5 is based on the 802.3 specifications of Project 802 developed by the Institute of Electrical and Electronic Engineers (IEEE).
10Base5 networks are wired together in a bus topology - that is, in a linear fashion using one long cable. The maximum length of any particular segment of a 10Base5 network is 500 meters, hence the 5 in 10Base5. If distances longer than this are required, two or more segments must be connected using repeaters. Altogether, there can be a total of five segments connected using four repeaters, as long as only three of the segments have stations (computers) attached to them. This is referred to as the 5-4-3 rule.
A 10Base5 segment should have no more than 100 stations wired to it. These stations are not connected directly to the thicknet cable as in 10Base2 networks. Instead, a transceiver is attached to the thicknet cable, usually using a cable-piercing connector called a vampire tap. From the transceiver, a drop cable is attached, which then connects to the network interface card (NIC) in the computer. The minimum distance between transceivers attached to the thicknet cable is 2.5 meters, and the maximum length for a drop cable is 50 meters. Thicknet cable ends have N-series connectors soldered or crimped on them for connecting segments together.
10Base5 networks were often used as backbones for large networks. In a typical configuration, transceivers on the thicknet backbone would attach to repeaters, which would join smaller thinnet segments to the thicknet backbone. In this way, a combination of 10Base5 and 10Base2 standards could support sufficient numbers of stations for a moderately large company.
10Base5 networks are legacy networks that are no longer implemented, although some companies might choose to maintain them for cost reasons. The complexity and bandwidth limitations of 10Base5 networks render them obsolete. If you are wiring an office for a small LAN with low bandwidth requirements, use 10BaseT instead. For moderate to high bandwidth requirements, try using Fast Ethernet. If you are implementing a backbone for today’s high-speed enterprise networks, try using Gigabit Ethernet, Fiber Distributed Data Interface (FDDI), or some other advanced technology.
The two ends of a 10Base5 bus must be properly terminated. If they are not, signals will bounce and network communications will be impossible.