10BASE2

10BASE2
7.1.3 This page covers 10BASE2, which was introduced in 1985.


Installation was easier because of its smaller size, lighter weight, and greater flexibility. 10BASE2 still exists in legacy networks. Like 10BASE5, it is no longer recommended for network installations. It has a low cost and does not require hubs.

10BASE2 also uses Manchester encoding. Computers on a 10BASE2 LAN are linked together by an unbroken series of coaxial cable lengths. These lengths are attached to a T-shaped connector on the NIC with BNC connectors.

10BASE2 has a stranded central conductor. Each of the maximum five segments of thin coaxial cable may be up to 185 m (607 ft) long and each station is connected directly to the BNC T-shaped connector on the coaxial cable.

Only one station can transmit at a time or a collision will occur. 10BASE2 also uses half-duplex. The maximum transmission rate of 10BASE2 is 10 Mbps.

There may be up to 30 stations on a 10BASE2 segment. Only three out of five consecutive segments between any two stations can be populated.

The next page will discuss 10BASE-T.

10BASE-T
7.1.4 This page covers 10BASE-T, which was introduced in 1990.


10BASE-T used cheaper and easier to install Category 3 UTP copper cable instead of coax cable. The cable plugged into a central connection device that contained the shared bus. This device was a hub. It was at the center of a set of cables that radiated out to the PCs like the spokes on a wheel. This is referred to as a star topology. As additional stars were added and the cable distances grew, this formed an extended star topology. Originally 10BASE-T was a half-duplex protocol, but full-duplex features were added later. The explosion in the popularity of Ethernet in the mid-to-late 1990s was when Ethernet came to dominate LAN technology.

10BASE-T also uses Manchester encoding. A 10BASE-T UTP cable has a solid conductor for each wire. The maximum cable length is 90 m (295 ft). UTP cable uses eight-pin RJ-45 connectors. Though Category 3 cable is adequate for 10BASE-T networks, new cable installations should be made with Category 5e or better. All four pairs of wires should be used either with the T568-A or T568-B cable pinout arrangement. This type of cable installation supports the use of multiple protocols without the need to rewire. Figure shows the pinout arrangement for a 10BASE-T connection. The pair that transmits data on one device is connected to the pair that receives data on the other device.

Half duplex or full duplex is a configuration choice. 10BASE-T carries 10 Mbps of traffic in half-duplex mode and 20 Mbps in full-duplex mode.

The next page describes the wiring and architecture of 10BASE-T.