Crimping Cables

Crimping Procedure
The correct type of cable must be selected and this must be Stranded UTP for a patch cable.
A suitable length of cable is cut.
At least 2 cm of the cable sheath has to be stripped to expose the inner pairs.
Then the pair of cables has to be untwisted.
The colored wires should be placed in the correct order using the wiring diagram according to the standard colour coding or EIA/TIA standards.
The inner wires should be cut such that they are exactly the same length and just long enough to reach the RJ45 connector with the bridge positioned over the cable sheath.
The connector has to be positioned with the spring lever at the bottom.
The wires are pushed into the connector such that the copper core should be visible from the end of the connector.
The wires have to be checked to see if they are in the correct order.
The RJ45 connector is pushed into the crimping tool and the handles are squeezed.
The cables are checked to see if they are pierced and the bridge is over the cable sheath.
The same procedure is repeated for the other end of the cable.
The cable is tested using a cable tester. This is useful in identifying any crossed wires or those which do not make contact.
Crimping Cables
Wiring for a UTP patch cable
The pairs of wires in UTP cable are colored so that you can identify the same wire at each end.
Furthermore they are usually color coded by pair so that the pairs can also be identified from end to end.
Typical CAT5 UTP cables contain 4 pairs made up of a solid colour and the same solid colour striped onto a white background.
The most common colour scheme is the one that corresponds to the Electronic Industry Association/Telecommunications Industry Association's Standard 568B.

White / Orange >> White / Orange
Orange >> Orange
White / Green >> White / Green
Blue >> Blue
White / Blue >> White / Blue
Green >> Green
White / Brown >> White / Brown
Brown >> Brown
Wiring for a cross-over cable
In order to make what is commonly referred to as a 'Crossover' cable one must change the pinout connections on ONE end of the cable.
If you do it on both ends of the cable you have crossed-over the crossover and now have a straight-through cable albeit a very non-standard one.
In this case two negatives do make a positive.

White / Orange >> White / Green
Orange >> Green
White / Green >> White / Orange
Blue >> Blue
White / Blue >> White / Blue
Green >> Orange
White / Brown >> White / Brown
Brown >> Brown

Structured Wiring Systems
Structured Wiring Systems
The computer network UTP is installed in the same manner as a telephone installation.
The main components are as follows:
A network card with a socket for an RJ45 (four pair) or RJ11 (two pair) connector.
A patch cable with the appropriate connector is used to link the network card into a wall jack.
This must be a stranded cable so that it is flexible.
Since the attenuation of stranded cable is higher than solid cable the length of this cable should not exceed 32 feet.
The cabling then passes into the wiring ducts at the back of the wall outlets and is routed to the main computer room.
Solid core cables are used as it is cheaper has lower attenuation and repeated flexibility is not required.
The cable is wired into the back of a patch panel in the computer room.
Lastly a patch cable connects the port on the front of the patch panel to free port on the hub.
Here again stranded cable should be used with a maximum length of 32 feet.

Wiring Techniques
The wall outlet and the patch panel have a punch down block for each port.
The following steps have to be completed to connect the wiring to a punch down block:
As little sheath as possible (about 3cm) is removed and the pairs are untwisted only for a maximum distance of half an inch.
Note: Excessive untwisting will allow excessive crosstalk between strands and may result in problems.
The pairs are laid over the appropriate location on the punch down block and a punch tool is used to simultaneously make connection and to cut the strand to length.
There are two formats in the punch down blocks - Krone and 110.
Appropriate punch tools are required for different formats.
The Electrical Industries Association introduced the EIA 568 specification in 1991.
This standard is called the 'Commercial Building Telecommunications Wiring Standard'.
This was the first non-proprietary networking scheme for network designers and has later been revised and updated culminating in the latest version of the TIA/EIA 568A.
Note:
The usage of special types of cables for specific situations may be required in case of local fires and safety regulations.
For example the use of plenum cable above the false ceilings in an office.
This cable is designed to be fire resistant and uses Teflon coatings so it produces a minimal amount of smoke.
PVC insulation should be avoided as this produces poisonous gas when burnt.