data centre cabling is probably the most important process in a data centre. Without data cables, a data centre is just another location or room with multiple computers and servers regardless of how powerful or efficient the servers are. Put simply, data cables connect two or more computers so that the computers are able to transmit data among themselves. Note that when data cables connect several computers (some of which are usually servers), the entire arrangement becomes a network.
Data centre cable management, obviously, is extremely important and it includes choosing the right cables and cabling the data centre intelligently. Your choice of cables should be driven by the topology and structure of the data centre network. The most popular cable types are coaxial, Ethernet crossover, twisted pair, and fibre optic. While you use each of them in different situations, all of the cable types follow certain common principles and operating procedures.
The basic principles or operating procedures of different network cable types are given below.
All cable types must comply with specific standards, or more specifically, Ethernet standards. The uniform standards are the keys to seamless integration among diverse equipments such as servers, client computers, printers and faxes.
Logical layer and physical layer
A computer network has two parts -- logical layer and physical layer. The logical layer comprises specific rules and standards which govern how the different equipments communicate with one another. The physical layer is the link through which different equipments transmit electronic signals. The hardware which maintains the connectivity among different devices also must comply with specific designs or architecture.
Ethernet cables have become the most popular cable type used in data centres. Earlier, coaxial cables were used. Now, most setups use optical fibre or twisted pair cables. The popularity of these cables has actually given rise to the term Ethernet cable which refers to the twisted cables. It is of course, a loosely - used term.
You need to use the twisted pair cables, also known as Category 5 or Cat 5 cables, in a specific manner. The cable contains inside it 8 individual 24 gauge copper wires which need to be grouped into 4 categories. Then, you need to twist the 4 pairs around one another. Usually, you may need to apply 3 twists. The spacing between twists depends on the cable. The twisting significantly reduces the possibility of signal interference from external sources.
The Category 5 cables are of two types -- crossover and straight-through. When you use a straight-through type for sockets and plugs, pins 1 and 2 transmit signals while pins 3 and 6 receive signals. The straight-through type connects computers to different network devices such as switches and hubs. In the case of a crossover setup, you need to reverse the assignations so that the transmitting plug pins can connect to the receiving socket pins. The crossover arrangement can directly connect computers. However, recently-released models of hubs, switches and routers can switch automatically between a crossover and a straight-through setup. So, you do not need to use two different Category 5 cables.