EXPERIMENT NO.
04
DATE OF PERFORMANCE: GRADE:
DATE OF ASSESSMENT: SIGNATURE OF LECTURER/ TTA:
AIM: IMPLEMENTATION OF VARIOUS CONNECTORS, NIC AND
CRIMPING TOOL IN NETWORKING.
THEORY:
COLOR CODES FOR RJ-45 ETHERNET PLUG:
Eight-conductor data cable (Cat 3 or Cat 5) contains 4 pairs of wires. Each pair consists of
a solid color wire and a white and color striped wire. Each of the pairs are twisted together.
To maintain reliability on Ethernet, you should not untwist them any more than necessary
(about 1/4 inch).
The pairs designated for 10BaseT Ethernet are orange and green. The other two pairs,
brown and blue, are unused. The connections shown are specifically for an RJ45 plug. The
wall jack may be wired in a different sequence because the wires may be crossed inside the
jack.
FIGURE 4.1: T-568B, RJ-45 PLUG AND T-568A
The illustration above shows both standards. With the T-568B specification the orange and
green pairs are located on pins 1, 2 and 3, 6 respectively. The T-568A specification reverses
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the orange and green connections, so that the blue and orange pairs are on the center 4
pins, which makes it more compatible with the telco voice connections.
The T-568A standard is supposed to be used in new network installations. Most off-the-
shelf Ethernet cables are still of the T-568B standard; however, it makes absolutely no
functional difference in which you choose.
FIGURE 4.2: T-568A STRAIGHT-THROUGH ETHERNET CABLE
FIGURE 4.3: T-568B STRAIGHT-THROUGH ETHERNET CABLE
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FIGURE 4.4: RJ-45 CROSSOVER ETHERNET CABLE
A good way of remembering how to wire a Crossover Ethernet cable is to wire one end
using the T-568A standard and the other end using the T-568B standard. Another way of
remembering the color coding is to simply switch the Green set of wires in place with the
Orange set of wires. Specifically, switch the solid Green (G) with the solid Orange, and
switch the green/white with the orange/white.
ETHERNET CABLE TIPS:
A straight-thru cable has identical ends.
A crossover cable has different ends.
A straight-thru is used as a patch cord in Ethernet connections.
A crossover is used to connect two Ethernet devices without a hub or for connecting
two hubs.
A crossover has one end with the Orange set of wires switched with the Green set.
Odd numbered pins are always striped, even numbered pins are always solid
colored.
Looking at the RJ-45 with the clip facing away from you, Brown is always on the
right, and pin 1 is on the left.
No more than 1/2" of the Ethernet cable should be untwisted otherwise it will be
susceptible to crosstalk.
Do not deform, do not bend, do not stretch, do not staple, do not run parallel with
power cables, and do not run Ethernet cables near noise inducing components.
Note: Odd pin numbers are always the striped wires.
Straight-Through vs Cross-Over:
In general, the patch cords that you use with your Ethernet connections are "straight-
through", which means that pin 1 of the plug on one end is connected to pin 1 of the plug
on the other end (for either standard). The only time you cross connections in 10BaseT is
when you connect two Ethernet devices directly together without a hub or connect two
hubs together. Then you need a "cross-over" patch cable, which crosses the transmit and
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receive pairs. An easy way remember how to make a cross-over cable is to wire one end
with the T-568A standard and the other with the T-568B standard.
FIGURE 4.5: STRAIGHT-THROUGH AND CROSSOVER
Crossover Cables:
Normal cables that connect a PC/NIC card to a hub are wired straight through. That is pin
1 is connected to pin 1, pin 2 to pin 2, etc. However, if you are simply connecting two PCs
together without a hub, you need to use a crossover cable made by reversing pair 2 and 3 in
the cable, the two pairs used for transmission by Ethernet. The easy way to make a
crossover cable is to make one end to T568A colour coding and the other end to T568B.
Then the pairs will be reversed.
FIGURE 4.6: CROSS OVER CRIMPING
CONNECTORS:
RJ-11:
Standard telephone cable connectors, RJ-11 has 4 wires (and RJ-12 has 6 wires). RJ-11 is
the acronym for Registered Jack-11, a four- or six-wire connector primarily used to
connect telephone equipment.
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FIGURE 4.7: RJ-11 CONNECTOR
RJ-45 (REGISTERED JACK):
The 8 Position 8 Contact (8P8C) modular plugs and jacks are communications connectors
These connectors are often referred to as RJ -45 Plugs and Jacks.
The acronym for Registered Jack-45 is RJ-45. The RJ-45 connector is an eight-wire
connector that is commonly used to connect computers to a local area network (LAN),
particularly Ethernet LANs. Although they are slightly larger than the more commonly
used RJ-11 connectors, RJ-45s can be used to connect some types of telephone equipment.
FIGURE 4.8: RJ-45 CONNECTOR
BNC CONNECTORS:
It is a BNC (Bayonet Neill–Concelman) connector is miniatures quick connect/disconnect
radio frequency connector for Co-axial cable.
FIGURE 4.9: BNC CONNECTOR
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USB CONNECTOR
There are 2 types of USB connector.
1. Type A
2. Type B
FIGURE 4.10: USB CONNECTOR
NETWORK INTERFACE CARD (NIC):
A network interface card (NIC) is a circuit board or card that is installed in a computer so
that it can be connected to a network. The NIC is also referred to as an Ethernet
card and network adapter. It is an expansion card that enables a computer to connect to a
network; such as a home network, or the Internet using an Ethernet cable with an RJ-
45 connector. A network interface card provides the computer with a dedicated, full-time
connection to a network. Personal computers and workstations on a local area network
LAN typically contain a network interface card specifically designed for the LAN
transmission technology.
FIGURE 4.11: NIC
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CRIMPING TOOL:
A crimping tool is a device used to conjoin two pieces of metal by deforming one or both of
them in a way that causes them to hold each other. The result of the tool's work is called
a crimp. A good example of crimping is the process of affixing a connector to the end of a
cable. For instance, network cables and phone cables are created using a crimping tool to
join the RJ-45 and RJ-11 connectors to the both ends of either phone or CAT5 cable.
FIGURE 4.12: CRIMPING TOOL (RJ-11 & RJ-45)
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