Q3 LESSON 3 - NETWORK CABLING

NETWORK CABLES- used to connect and transfer data and information between computers, routers, switches, and storage area networks. These cables are essentially the carrier or media through which data flows.

    There are different types of communications cables and the appropriate type to use will depend on the structure and topology of the overall architecture of the system. The most commonly used types of communication cable are dominated by what is referred to as "twisted pair cable". In local area networks; typically, office environments, retail, and commercial sites, copper communications cabling, i.e., twisted pair cable is by far the most commonly used type of cable.

TWISTED PAIR- is used in many ethernet works. Comprising of four pair of thin wires or conductors, these wires or conductors are contained inside of the insulation or outer sheath of the cable. Each pair is twisted into several additional twists. These twists are designed to prevent interference from other devices and indeed from other adjacent cables.

STRAIGHT THROUGH AND CROSSOVER CABLE

STRAIGHT THROUGH- a type of twisted pair cable that is used in local area networks to connect a computer to network hub such as a router. This type of cable is also sometimes called a "patch panel" and is an alternative to wireless connections where one or more computers access a router through a wireless signal. On a straight through cable, the wired pins match. 

    Straight through cable use one wiring standard: both end use T568A wiring standard or both end use T568B wiring standard. The following figure shows a straight through cables of which both ends are wired as the T568B standard.

CROSSOVER CABLE- is a type of Ethernet cable used to connect computing devices together directly. Unlike straight through cable, the RJ45 crossover cable use two different wiring standards: one end used the T568A wiring standard and the other end use the T568B wiring standard.

    

    The internal wiring of Ethernet crossover cables reverses the transmit and receive signals. It is most often used to connect two devices of the same type: e.g. two computers (via network interface controller) or two switches to each other.

 STRAIGHT THROUGH VS CROSSOVER CABLES

STRAIGHT THROUGH- primarily used for connecting unlike devices.

USE STRAIGHT THROUGH ETHERNET CABLE FOR THE FOLLOWING CABLING;

• Switch to Router
• Switch to PC or Server
• Hub to PC or server 

CROSSOVER CABLE- used for connecting alike devices.

USE CROSSOVER CABLES FOR THE FOLLOWING CABLING;

• Switch to Switch
• Switch to Hub
• Hub to Hub
• Router to Router
• Router to Ethernet port to PC NIC
• PC to PC

TO CREATE A NETWORK (ETHERNET) CABLE, YOU NEED THE EQUIPMENT LISTED BELOW;

1. CAT 5, CAT 5e, CAT 6, or CAT 7 CABLE- this cabling can be purchased in large spindles at stores that specialize in cabling. CAT 5 cabling is the most commonly used cable today for networks.
2. RJ-45 CONNECTORS- these connectors can be purchased at most electronic stores and computer stores and usually come in bulk packages. It is always a good idea to get more than you think you need.
3. CRIMPING TOOL- these are often purchased at electronic stores. To create a network cable, you need a crimper that is capable of crimping a RJ45 cable (not only a RJ11 cable, which looks similar to an RJ45)
4. WIRE STRIPPER OR KNIFE- if you plan on making several network cables, also consider getting a wire stripper cable of stripping CAT 5, CAT 6, or your cable of choice. If you don't plan on creating many network cables, a knife will suffice. To prevent potential issues, we recommend a wire stripper.

 CREATING NETWORK CABLE (STRAIGHT THROUGH CABLING)

1. Memorize the color code combination before doing the activity.
2. Cut into the plastic sheath or insulator about 1 inch (2.5 cm) from the end of the cable. Strip off after cutting. The crimping tool has a razor blade that will do the trick with practice.
3. Unwind and pair the similar color.
4. Pinch the wires between your finger and straighten them out as shown. The color order is important to get correct. Position all eight wires according to its designed pins in the RJ45.
5. Use either the wire cutter in the crimping tool or scissors to make a straight cut across the 8 wires to shorten them to 1/2 inch (1.3 cm) from the cut sleeve to the end of the wires. 
6. Carefully push all eight (8) unstripped colored wires into the RJ45. Note: the position of the plastic sleeve or insulators. Also note how the wires go all the way to the end. Make sure all the wires reach the pins.
7. Crimping the cable. Carefully place the connector into the crimping and pinch down on the handles tightly. The copper splicing tabs on the connector will pierce into ech of the eight wires. There is also a locking tab that holds the plastic sleeve or insulator in place for a tight compression fit. When you remove the cable from the crimper; that end is ready to use.
8. Repeat steps another end. For a standard "straight through" cable, repeat all steps and wire color order on the other end of cable. For crossover cable, the other end will have a different color order. Use LAN tester to test functionality.