the hong kong polytechnic university - PolyU

the hong kong polytechnic university - PolyU
THE HONG KONG POLYTECHNIC UNIVERSITY
Department of Electronic and Information Engineering
ENG224 Information Technology
Laboratory 5
Network Wiring and Testing
Objectives:
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•
•
•
Build a straight-through Ethernet cable according to T568-B standard
Build a crossover Ethernet cable according to the T568-A and T568-B standards
Wire an RJ-45 data jack
Use a cable tester to verify that the cables are in good condition
Tools:
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•
•
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Unshielded Twisted Pair (UTP) copper cables
RJ-45 connectors and RJ-45 crimping tools
Wire cutters
RJ-45 data jacks
Punch down tool
Cable Tester with an RJ45-RJ45 female coupler and a cable identifier (Fluke 620 or equivalent)
Introduction to Straight-Through Cable:
In this section, you will learn how to build a Category 5 (Cat 5) Unshielded Twisted Pair (UTP) Ethernet
straight-through cable, and test it for good connection and correct pinouts. The straight-through cable can be
used for connecting a computer to an Ethernet hub/switch. The straight-through cable, as its name tells, will
have the same wire at the same pin on both ends of the cable. For instance, the wire at Pin-1 on one end will
be the same at Pin-1 on the other end. We will follow either the structured cabling standard T568-A or
T568-B. Fig. 1 and Fig. 2 show the T568-A and T 568-B wire colors, respectively. Table I and Table II list
more information of the T568-A and T568-B cabling standards.
Pair 2
Red
Pair 3
Green
Pair 3 Pair 1 Pair 4
Green Blue Brown
Pair 2 Pair 1 Pair 4
Red
Blue Brown
1 2 3 4 5 6 7 8
1 2 3 4 5 6 7 8
Fig. 1: T568-A cabling standard.
Fig. 2: T568-B cabling standard.
(Note: Both diagrams show the wiring arrangement when viewed into an
Ethernet socket, with the prong on the underside.)
Pin#
Pair#
Function
Wire Color
1
2
3
4
5
6
7
8
3
3
2
1
1
2
4
4
Transmit
Transmit
Receive
Not used
Not used
Received
Not used
Not used
White/Green
Green
White/Orange
Blue
White/Blue
Orange
White/Brown
Brown
Used in 10Base-T and
100Base-T Ethernet?
Yes
Yes
Yes
No
No
Yes
No
No
Used in 100Base-T4 and
1000Base-T Ethernet
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Page 1
Table I: Information of T-568A cabling standard.
Pin#
Pair#
Function
Wire Color
1
2
3
4
5
6
7
8
2
2
3
1
1
3
4
4
Transmit
Transmit
Receive
Not used
Not used
Receive
Not used
Not used
White/Orange
Orange
White/Green
Blue
White/Blue
Green
White/Brown
Brown
Used in 10Base-T and
100Base-T Ethernet
Yes
Yes
Yes
No
No
Yes
No
No
Used in 100Base-T4 and
1000Base-T Ethernet
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Table II: Information of T568-B cabling standard.
Procedure of Building a Straight-Through Cable ? Same standard at both ends
(Note: A straight through cable can be made either by following the T568-A standard at both ends, or by
following the T568-B standard at both ends. It is possibly more common to use the T568-B standard and so
we will follow the T568-B standard in this exercise.)
1. Cut a piece of Cat 5 UTP cable to a suitable length (about 30cm).
2. Strip 1–2 cm of the plastic outer jacket off one end of the cable using the wire cutter. There should
be 4 pairs of colored wires inside.
3. Re-organize the 8 wires into the order according to the T568-B cabling standard. (Note: The plastic
insulation on the individual wires need not be removed.)
4. Flatten, straighten and align the wires. Then trim them in a straight line to within about 1 cm from
the edge of the outer jacket.
5. Place an RJ-45 plug at the end of the cable, with the prong on the underside and the red pair of wires
on the leftmost side of the connector (for T568-B cabling standard).
6. Gently push the wires onto the plug until the ends of the wires reach the end of the plug. Make sure
the end of the outer jacket is inside the plug (otherwise, the wires will easily be shaken off the plug
and the electrical connection will be broken) and all wires are in the correct order.
7. Crimp the plug hard using the RJ-45 crimping tool to force the contacts through the insulation on the
4 pairs of wires.
8. Repeat steps 2-7 to terminate the other end of the cable using the same cabling standard (i.e. T568-B)
to finish a straight-through cable.
Procedure of Cable Testing
To test the electrical conditions of the cable, a cable tester (Fluke 620 LAN cable meter or equivalent) will
be used. Three conditions, namely the continuity, cable length and wire map, of the cable will be tested.
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•
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Continuity test ? Check the continuity of the wires, i.e. check if the wire on one end can conduct
electricity to the wire on the other end.
Cable length ? Check the length of each pair of wires of the cable.
Wire map ? Determine whether the wires are correct at both ends of the cable.
In addition, the tutors will check the mechanical conditions of the cable (e.g. whether the end of the outer
jacket is inside the plug, and/or whether the wires will easily be shaken off from the plug).
Continuity Test
1. Turn the rotary switch of the cable tester to the TEST position. Press the SETUP button once to
enter the setup mode. Use the UP, DOWN or ENTER button to set the tester options as in Table III.
2. Place the near end of the cable to be tested into the RJ-45 jack UTP/FTP on the tester. Place the
RJ45-RJ45 female coupler on the far end of the cable and then insert the cable identifier into the
other side of the coupler.
Page 2
Tester Option
CABLE:
WIRING:
CATEGORY:
WIRE SIZE:
CAL to CABLE?
BEEPING:
LCD CONTRAST:
Desired Settings
UTP
10 BASE-T 2PR or EIA/TIA 4PR
CAT 5
AWG 24
NO
ON or OFF
From 1 to 10 (brightest)
Table III. Tester Options
3. Press the Enter button to enter the testing mode. Write down the test results on the LCD of the cable
tester in your laboratory report.
Continuity test result: _________________________________________________________________
ID#:
Length: ______________________________________
Length Test
4. Keep the same tester options in step 1. Turn the rotary switch selector to the LENGTH position.
Write down the results on the LCD of the cable tester in your report.
;
;
; ___________________
What are the meanings of the numbers displayed at the left and right of the LCD of the cable tester?
___________________________________________________________________________________
___________________________________________________________________________________
Wire Map
5. Keep the same tester options in step 1. Turn the rotary switch selector to the WIRE MAP position.
Write down the results on the LCD of the cable tester in your report.
___________________________________________________________________________________
___________________________________________________________________________________
What are the meanings and relationships between the numbers on the first and second rows?
___________________________________________________________________________________
___________________________________________________________________________________
Inspection by Tutor
6. Show your cable and test results to a tutor. Your tutor will check the mechanical conditions of the
cable. When your tutor is satisfied with your work, he/she will sign on your logbook or lab sheet to
confirm that you have successfully made a straight-through UTP cable.
Crossover Cable ? T568 -A at one end and T568 -B at the other end:
In this section, you will learn how to build a CAT 5 UTP Ethernet crossover cable and test it for good
connection and correct pinouts. The crossover cable is for direct connection between two workstations (or
two switches). It will be built based on the structured cabling standards, T568-A and T568-B. The pinouts
will follow T568-A on one end and T568-B on the other end of the cable.
Build a crossover cable and test it using the cable tester by following the procedures in the previous section.
Test the cable using the same tester options as listed in Table III.
Page 3
Continuity Test
1. Turn the rotary switch selector of the cable tester to the TEST position and write down the testing
results for the crossover cable in your report.
Continuity test:
ID#:______________________________________
Remarks: ___________________________________________________________________________
Length Test
2. Turn the rotary switch selector of the cable tester to the LENGTH position and write down the
testing results of your crossover cable in your report.
; ___________________________________________
; ___________________________________________
Wire Map
3. Turn the rotary switch selector of the cable tester to the WIRE MAP position and write down the
testing results of your crossover cable in your report.
___________________________________________________________________________________
___________________________________________________________________________________
Inspection by Tutor
4. Show your cable and test results to your tutor. Your tutor will check the mechanical conditions of
the cable. If he/she is satisfied with your work, he/she will sign on your logbook or lab sheet to
confirm that you have successfully made a cross-over UTP cable.
RJ-45 Outlet:
In this section, you will learn how to wire an RJ-45 data jack using a punch-down tool. A CAT 5 straightwired cable with an RJ-45 plug will normally be slotted into this outlet to connect a PC to the network.
1. Remove 1–2 cm of the jacket from the end of the cable. Again there is no need to remove the
plastic insulation on the individual wires.
2. Position the wires into the proper channels of the jack according to the T568-B standard below.
Wire color
White Orange
Orange
White Green
Blue
White Blue
Green
White Brown
Brown
Channel or slot # of the
8-pin receptacle
1
2
3
4
5
6
7
8
Table IV. Wiring color scheme for T568-B jack.
3. Use the punch-down tool to push each wire into its own channel of the jack.
4. Use the cable tester to test the electrical connection of the data jack you’ve made.
5. Show the data jack and test results to your tutor. Again your tutor will sign on your logbook to
confirm that you have successfully made an RJ-45 data jack.
- End Page 4
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