Chap 9 Structure Cabling Project

Andres, Wen-Yuan Liao

Department of Computer Science and Engineering

De Lin Institute of Technology

andres@dlit.edu.tw

http://www.cse.dlit.edu.tw/~andres

RJ-45 jack

One side of the RJ-45 jack contains eight color-coded slots

The other side of the jack is a female plug, which looks like a standard phone jack, except that the RJ-45 jack is larger and has eight pins

Surface-mounting an RJ-45 jack

Two types of boxes Screw-mounted boxAdhesive-backed box

Flush-mounting an RJ-45 jack

If you do choose to place the jack on a wood baseboard, avoid cutting the opening into the bottom 5 cm of the baseboard

The wall's bottom plate will block you from pushing it in

Safety Procedure

Any time you are working in walls, ceilings, or attics, it is extremely important that you remember to turn off the power to all circuits that go to, or pass through, the work area!

Procedure for placing the copper wires into a jack

When you use RJ-45 jacks at the telecommunications outlet in a horizontal cabling scheme, the wiring sequence is critical to ensure the best possible network performanceTo punch down the wires into the jack, you need to use a punch tool

Documenting cable runs Whenever you install cable, it is important that you document your actionsA cut sheet is a rough diagram that shows the locations of the cable runsThe numbers of the classrooms,

offices, or other rooms, to which the cables have been run

Types of labels

Label each cable connection at the patch panel in the wiring closet

Place the connections so that the labels are arranged in ascending order

This allows easy diagnosis and location of problems

Label the cables at each end

Preparing cable for routing and labeling

Spools are usually packaged in boxes

To help you keep track of each cable as it comes off its spool, assign a letter to each spool

Easiest procedure for routing cable

To wall mount cable you need to select a device that will secure it to a wall. One such device is the tie-wrap

Mounting cable in raceway

Raceway is a wall-mounted channel

decorative raceway - presents a more finished appearanceEnclose cable on a wall inside a

room where it might otherwise be visible

Gutter raceway - a less attractive alternative to decorative racewayBig enough to hold several

cablesBe restricted to spaces such

as attics and spaces created by dropped ceilings

Running cable through existing raceway

Can you think of any types of cable that you would not want to run next to CAT 5 UTP cable? This would include any type of power or electrical cable

Personal safety precautions before installing cable

Whenever you work in walls, ceilings, or attics, the first thing you should do is turn off power to all circuits that might pass through those work areas! Before you begin work, learn the locations of all fire extinguishers in the area

Wear appropriate clothingLong pants and sleeves help protect your arms and legs

Avoid wearing excessively loose or baggy clothing

If it is catches on something, you could be injured

If you anticipate working in a dropped ceiling area, survey the area. You can do this by lifting a few of the ceiling tiles and looking around

If you need to cut or saw, protect your eyes with safety glasses

Consult the building's maintenance engineer

Keep your work area orderly and neat

Building safety

Some building codes may prohibit drilling or cutting holes in certain areas such as fire walls or ceilings

If you find that you must route cable through spaces where air is circulated, you will need to use a fire-rated cable

Wiring closet

A wiring closet serves as a central junction point for the wiring and wiring equipment used to connect devices in a local area network (LAN)

MDFs and IDFs

One wiring closet is designated as the main distribution facility (MDF)

All others, referred to as intermediate distribution facilities (IDFs)

Patch panel

A patch panel acts as a switchboard, where horizontal cables coming from workstations, can connect to other workstations to form a LAN

Mounting a patch panel

The advantage of a distribution rack is that it allows easy access to both the front and the back of the equipment

Network operation testing The baseline is a record of your network's starting point or newly installed performance capabilities

You should continue to test your network

You can do this by comparing current measurements with recorded measurements that were taken when the system was known to be operating properly

Cable testers and distance measurements

Cable testers, sometimes referred to as time domain reflectometers (TDRs), measure the distance to open-ended, or shorted, cable

TDRs (time domain reflectometers)

A TDR measures distance on a cable by sending an electrical signal through the cableThe signal is reflected when it encounters the most distant open connection

Split pairs

Visual inspection and crosstalk measurements are the only ways to detect a condition known as split pairs.

When wires split, they are no longer part of the same circuit

The signals are not protected

Signal attenuation

A cable tester can measure the reduction in power of a signal received from a device known as a signal injector - attached to the far end of a cableCable testers generally measure attenuation at several frequencies

Causes of NEXT Twisted pairs that have become untwisted After being attached to cross-

connect devices Cables that have been pulled too

tightly around sharp corners,

If you measure near-end crosstalk, you should do a visual check of the horizontal cabling

Summary

Structure cabling