Question

. Describe the equipment (cable tester) needed and the steps to be followed to test the patch cable and the crossover cables to verify they have been properly assembled.                                                                      

Answer 1

The cable tester also called as LAN tester is one of the basic devices come across in a computer networking environment.

In a computer network where ethernet cables are used as the communication medium the reliability and proper connectivity of the cable across the entire network is to be ensured.

A cable tester is a device that can be used to test whether the cables are assembled and configured in the right way or not.

Ethernet cables

• Ethernet cables are made up of different pairs of wires with specific color code.
• A CAT-6 cable will be having 4 pairs of cables and the different configuration of ethernet cables are achieved by connecting the pairs in particular order.
• Also, the connectors for the ethernet cables are RJ45 or RJ11 connectors and their keystone connectors which also require a particular type of tools and techniques (crimping and punching) to make an ethernet cable.

Hence the chances of wiring up the wrong pairs or faulty connection will cause the failure of the entire network portion that connected using the cable.

In order to avoid that a cable tester can be used to verify the configuration of the cables.

A cable tester is made up of two parts, Master and remote each having their own 8-LED indicators for indicating the connectivity and ports for connecting RJ45 (Computer network) and RJ11 (telephone cables) cables

• The testing is started by turning the device on and connecting the one end of the cable in the master and another end of cable in the remote.
• The next step is to observe the LED pattern of the indicators to verify the correctness of the cable.

There are two types of cable configuration to connect the cable to the connector

Type A and Type B

The Patch cable

• a patch cable is a cable that connects the network-end device like a switch to the computers
• A patch cable is a straight-through cable used for connecting to unlikely devices in the networks
• the LAN cable configuration for straight-through cable is one to one connection that is, the pin 1 of one end will connect to pin 1 of the other end, pin 2 to pin 2 and likely till pin 8 to pin 8
• that is the same type of color-coding on both connectors of the cable.

In order to verify the patch cable for the correct assembly, both the master and remote of the cable tester show the same LED on the same order from 1 to 8 at the same time.

Any other pattern on the tester indicates a faulty pair combination or miswiring.

The Crossover cable

• a crossover cable is used to connect the same type of devices in the network like a router to router connection.
• The cable configuration is, type A coding on one side and type B coding on another side
• That is the pin connection will be like

End 1-Type A	End 2-Type B
PIN-1	PIN-3
PIN-2	PIN-6
PIN-3	PIN-1
PIN-4	PIN-4
PIN-5	PIN-5
PIN-6	PIN-2
PIN-7	PIN-7
PIN-8	PIN-8

In order to verify a crossover cable, the light pattern of the master and remote should be in the pattern of the above table

that is LEDs

• 1 and3,
• then 2 and 6,
• then 3 and 1,
• 4 and 4,
• 5 and 5,
• 6 and 2
• 7 and 7 and
• finally 8 and 8

should blink together

Any other pattern on the tester indicates a faulty pair combination or miswiring.