Network Cabling Standards

Network cabling standards can be quite confusing. Which type of cable is used with what? This tutorial will clear up some of that confusion

Network cables are known by both their construction and their ability to handle data transfer. Twisted Pair cables have ratings such as category 3, 5, 5e and 6. The higher the cat rating, the higher the data throughput it is rated for.

Lets start off with the old coax cabling. Coaxial cabling was used in early networks to connect nodes in a configuration to make a network. There were two types used in networking. 10BASE2 and 10BASE5.

To understand these technologies, lets break down what the standards mean. the "10" meant 10 megabits per second using Baseband (BASE) signaling at a maximum segment length of 185 meters (2). This used a thin coax and was often called "thinnet" as a result. Thinnet used BNC connectors to connect computers to a trunk that ran through a work area connecting all of the computers, printers, servers, switches, etc. to the network.

Thicknet on the other hand was a thick coaxial cable that was often termed a "frozen garden hose". It was usually yellow in color and was very stiff and hard to bend. The standard of 10BASE5 was followed in this technology. The difference was that the thicker cable could transfer data reliably in a segment of up to 500 meters in length. Still 10 Mb (small b= bits, Big B=bytes) per second transfer rate using Baseband signaling.

Most networks today are of the Ethernet variety and follow the 802.3 standards using twisted pair cabling and are known as 10BaseT, 100BASET,1000BASET, a TX at the end means that it is capable of full duplex communication. This cabling costs a lot less which has made it the cabling of choice for networks. There are different types of twisted pair cabling in use today. Most cables running inside the walls of a building, also known as "horizontal cabling", uses either a sheilded (STP) variety if it is passing near lights and other sources of interference or an unsheilded (UTP) variety if not. They use solid conductors rather than braided and are slightly stiff to bend. The patch cables that are commonly used to attach nodes to the network are of a braided conductor variety and easily bend and are not as brittle as a solid conductor.

category	Speed	Max Segment Length	Nodes Pairs	CableType	Pairs used
CAT 3	10 Mbps	100 Meters	1024	10BaseT	2
CAT 5	100 Mbps	100 Meters	1024	100BaseT 100BaseTX	2 4
CAT 5e	1000Mbps	100 Meters	1024	1000BaseT 1000BaseTX	4 4
CAT 6	1000Mbps	100 Meters	1024	1000BaseT 1000BaseTX	4 4

When you see the TX such as 100BaseTX, that means that the network is capable of full duplex communication. This is just like a telephone, it can send packets and receive packets at the same time. To accomplish this, all nodes must be connected to a port on the switch. No hubs in the network sharing bandwidth can be used. Each node must be in it's own collision domain, no other nodes attached to he same segment. This effective doubles the speed of the data on the network. Using a 1000BaseTX network is effectively two Gigabits per second of data transfer.