02 Laboratory Exercise 1

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02 Laboratory Exercise 1 *Property of STI Page 1 of 11

Laboratory Exercise Terminating CAT5 with RJ45 (T568B and T568A Plugs) and Punch Down Style Keystone Jacks Objectives: At the end of the exercise, the students should be able to:

properly terminate CAT5 UTP cable with two RJ45 modular plugs, using the T568B configuration,

properly terminate CAT5 UTP cable with two RJ45 modular plugs, using the T568A and T568B

configuration, and

properly terminate CAT5 UTP cable with punch down style keystone jacks.

Materials:

Cat5 UTP cable

RJ-45 connectors

Crimping tool

Wire stripper or Knife

CAT5 Keystone Jack 90 Degree 110 UTP

110 Punchdown Tool Basic Principles: Twisted pair cable and RJ-45 Connector

At present, both CAT5E and CAT6, handles bandwidths and throughputs of up to 100 MHz/1,000 Mbps and

200-250 MHz/10,000 Mbps, respectively. Also, both of them are connected using RJ-45 connectors that

should be wired to either the 568A or 568B standard (shown in Figure 1). RJ-45 connector is an 8-position

modular connector that is similar but larger than the RJ-11 which is historically used for telephones.

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Figure 1 Color Coding and Pin Outs of TIA/EIA T568B and T568A Standards

Figure 2 Straight - Through Ethernet Cable

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Figure 3 RJ-45 Crossover Ethernet Cable

The T568B/T568B was chosen for the straight through cable (shown in Figure 2) and T568B/T568A for the

cross-over cable (shown in Figure 3). It is also possible to wire it the opposite way (i.e., T568A/T568A straight

through). Your choice might be determined by the need to match existing wiring, jacks or personal preference,

but you should maintain consistency.

Procedures:

NOTE: Please observe safety precautions and proper handling while conducting the laboratory experiment.

This experiment is to be performed under instructor’s supervision.

Activity 1: Terminating CAT5 with RJ45 (T568B and T568A Plugs)

FOR STRAIGHT THROUGH CABLE

1. Pull the cable off the reel to the desired length and cut.

Note: The total length of wire segments between a PC and a hub or between two PC's cannot exceed

100 Meters (328 feet) for 100BASE-TX and 300 Meters for 10BASE-T.

2. Start on one end and strip 1 – 1½” of insulating sheath of the cable using a wire stripper or a knife.

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Note: Be extra careful not to cut into conductor insulation. Damaging one of the 8 wires, even if you

just nick it or partially cut it, will ruin your cable.

Figure 4 Stripped Cable Jacket

3. Spread, untwist the pairs, and reorganize the cable pairs according to the wires color coded as

follows: blue/blue-white, orange/orange-white, green/green-white, and brown/brown-white.

Figure 5 Untwisting the Cable Pairs

Figure 6 Grouping Individual Pairs

4. Now align the wires in the following order from left to right: white-orange,orange, white-green,blue,

white-blue,green, white-brown,brown.

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Figure 7 T-568B Standard

5. Get the wires lined up and nice, and straight through flattening the ends of the wires between your

thumb and forefinger. Trim all wires evenly, leaving about ½” in wire length. If it is longer than ½" it will

be out-of-spec and susceptible to crosstalk.

Figure 8 Trimming the CAT5 Conductors

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Figure 9 1/2 in wire length

6. Place an RJ45 plug on the end of the cable.

7. Hold the RJ-45 plug with the copper connectors up and clip facing down or away from you.

8. Gently push the plug onto the wires until you can see the copper ends of the wires through the end of

the plug.

9. Inspect each wire is flat even at the front of the plug. Check the order of the wires. Double check

again.

10. Check that the jacket is fitted right against the stop of the plug.

Note: If the jacket is not inside the plug, it will not be properly strain-relieved and will eventually cause

problems.

Figure 10 Inserting the CAT5 Conductors

If everything went well, it should look like this: Right:

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Figure 11 Properly Rested Cable Sheath

Wrong:

Figure 12 Not properly rested cable sheath

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Figure 3.12 shows how a cable sheath should NOT look. Wires of the image shown on top were left

too long, which leaves wires unprotected between the RJ-45 and the insulation. On the other hand,

the wires of the lower image were cut too short and now don’t reach far enough to make contact.

11. Check the color orientation, check that the crimped connection is not about to come apart, and check

to see if the wires are aligned correctly and flat against the front of the plug.

Note: Even if one of these are incorrect, you will have to start over.

12. Then insert the RJ-45 connector into the appropriate opening of the crimping tool. Carefully hold the

wire and squeeze firmly to crimp the RJ-45 with the crimper without crushing it.

Figure 13 Using the Crimping Tool to crimp RJ-45

13. Now repeat this entire procedure to put an RJ-45 plug on the other end of the cable. Use the exact

same wiring scheme as on the first end, which will make it a straight-through cable.

14. Once your cable is finished, test it with a cable tester to make sure it works.

15. Insert the two ends of the cable into the jacks on the tester and watch the two separate bars of

indicator lights (each with 8 lights) as the test sequence is completed, wire-by-wire.

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Note: If they (both the “input” and “output” indicators for each wire) all light up, you have a good

connection for each wire. A dim light indicates poor connection, and no light at all let you know that

connection is not made.

Figure 14 Cable Tester

FOR CROSSOVER CABLE

1. The cross-over cable can be made using the same steps as the straight-through cable. The only

difference is the order in which the wires are put, since the green and the orange pair trade places,

which makes it a cross-over cable. The wires color coded in this cable is as follows: white-

green,green, white-orange,blue, white-blue,orange, and white-brown,brown.

Question: 1. What have you noticed in the cable tester while testing the two cables? Record your observation in

the space provided.

Observation:

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Activity 2: Terminating CAT5 with Punch Down Style Keystone Jacks

1. Repeat procedures 1 and 3 of Activity 1 shown in Figure 16.

Figure 15 Procedures 1 to 3 of Activity 1

2. Straighten the pairs out completely and lay them over the top of the keystone jack (shown in Figure

17) noting the color pattern for the T568B wiring (white-orange, orange, white-green, blue, white-blue,

green, white-brown, brown).

Note: Each keystone jack is slightly different in how they are labeled and how the colors are

arranged. The 568B standard is most commonly used and ends of the cable must have the same

standards to communicate. Figure 18 below has the 2 standard pairs on the right, and the 2 variable

pairs on the left.

Figure 16 CAT5 Keystone Jack 90 Degree 110 UTP

Figure 17 CAT5 Keystone Jack 90 Degree 110 UTP

Front View

3. Keep the pairs as twisted as possible and press the wire into the correct groove (shown in Figure 19) with your thumb. Note: If you completely straighten the wires to run them through the jack you will risk

cross talk between the pairs.

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Figure 18 Wire into the correct groove

4. Using a punch down tool, punch the wires down into the blades built into the keystone jack (shown in

the Figure 20 below).

Note: The blades in the jack are designed to work with solid cable, and may not work with stranded

cable. Make sure the blade (as noted in the middle part of the Figure) is facing the outside of the

keystone jack. If you reverse it, you will cut the wires inside the keystone jack rendering them useless.

The punch down tool should cut off the remaining pieces of the wire on the outside, but sometimes

you may need to punch them down again and wiggle the wire to keep it well arranged. Once this is

done, you can install the dust covers if your keystone jack comes with them. This keystone jack does

not have the covers. The covers should never be used to do the job of the punch down tool.

Figure 19 Punch down tool

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02 Laboratory Exercise 1