Tapping Prevention

Tapping is the interception of LAN EM signals through listening devices placed around the
cable. Some tapping devices are invasive and will actually puncture the outer jacket of a cable,
or the insulation of individual wires, and touch the metal inner conductor to intercept all signals
sent along that conductor. Of course, taps can be applied at the cross-connects if security
access to your equipment rooms and telecommunications rooms is lax.
To prevent taps, the best course of action is to install the cables in metal conduit or to use
armored cable, where practical. Grounding of the metal conduit will provide protection from
both EM and invasive taps but not from taps at the cross-connect. When not practical, otherwise
securing the cables can make tapping much more difficult. If the person trying to tap your
communications can’t get to your cables, they can’t tap them. So you must install cables in
secure locations and restrict access to them by locking the cabling closets. Remember: If you
don’t have physical security, you don’t have network security.

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How to do Fire Protection

All buildings and their contents are subject to destruction and damage if a fire occurs. The
cabling in a building is no exception. You must keep in mind a few cabling-design concerns to
prevent fire, smoke, or heat from damaging your cabling system, the premises on which they
are installed, and any occupants.Another concern is the puncturing of fire barriers. In most residential and commercial buildings,
firewalls are built specifically to stop the spread of a fire within a building. Whenever
there is an opening in a floor or ceiling that could possibly conduct fire, the opening is walled
over with fire-rated drywall to make a firewall that will prevent the spread of fire (or at least
slow it down). In commercial buildings, cinder-block walls are often erected as firewalls
between rooms.
Because firewalls prevent the spread of fire, it is important not to compromise the protection
they offer by punching holes in them for network cables. If you need to run a network cable
through a firewall, first try to find another route that won’t compromise the integrity of the
firewall. If you can’t, you must use an approved firewall penetration device
These devices form a tight seal around each cable that passes through the firewall. One type of
seal is made of material that is intumescent; that is, it expands several times its normal size when
exposed to very high heat (fire temperatures), sealing the hole in the firewall. That way, the
gases and heat from a fire won’t pass through.

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How to do Cabling Management part 2

Standoffs
When terminating UTP wires for telephone applications in a telecommunications room, you
will often see telephone wires run from a multi-pair cable to the 66-punch-down block. To be
neat, the individual conductors are run around the outside of the board that the punch-down
blocks are mounted
D-Rings
For LAN installations that use racks to hold patch panels, you need some method of keeping
the cables together and organized as they come out of the cable trays and enter the telecommunications
room to be terminated. On many racks, special metal rings called D-rings (named
after their shape) are used to keep the individual cables in bundles and keep them close to the
rackIn addition to managing cable for a cabling rack, D-rings are also used on punch-down
boards on the wall to manage cables, much in the same way standoffs are. D-rings are put in
place to support the individual cables, and the cables are run to the individual punch-down
blocks on the wall.

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How to do Cabling Management part1

Conduit
The simplest form of cable protection is a metal or plastic conduit to protect the cable as it travels
through walls and ceilings. Conduit is really nothing more than a thin-walled plastic or
metal pipe. Conduit is used in many commercial installations to contain electrical wires. When
electricians run conduit for electrical installation in a new building, they can also run additional
conduit for network wiring. Conduit is put in place, and the individual cables are run inside it.
The main advantage to conduit is that it is the simplest and most robust protection for a network
cable. Also, if you use plastic conduit, it can be a relatively cheap solution (metal conduit
is more expensive).
Cable Trays
When running cable, the cable must be supported every 48 to 60 inches when hanging horizontally.
Supporting the cable prevents it from sagging and putting stress on the conductors
inside. For this reason, special devices known as cable trays (also sometimes called ladder racks,
because of their appearance) are installed in ceilings. The horizontal cables from the telecommunications
rooms that run to the individual telecommunications outlets are usually placed
into this tray to support them as they run horizontally.

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How to do Cabling Management

Cabling management is guiding the cable to its intended destination without damaging it or its
data-carrying capabilities. Many different cabling products protect cable, make it look good,
and help you find the cables faster. They fall into three categories:
● Physical protection
● Electrical protection
● Fire protection
In this section, we will look at the various devices used to provide each level of protection and
the concepts and procedures that go along with them.
Physical Protection
Cables can be fragile—easily cut, stretched, and broken. When performing a proper cabling
installation, cables should be protected. Many items are currently used to protect cables from
damage, including the following:
● Conduit
● Cable trays
● Standoffs
● D-rings
We’ll take a brief look at each and the different ways they are used to protect cables from damage.

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About HVAC Considerations

Computer and networking equipment generates much heat. Place enough equipment in a telecommunications
room without ventilation, and the temperature will quickly rise to dangerous
levels. Just as sunstroke affects the human brain, high temperatures are the downfall of electronic
components. The room temperature should match the ambient temperature of office
space occupied by humans, and keep it at that temperature year round.
For this reason, telecommunications rooms should be sufficiently ventilated. At the very
least, some kind of fan should exchange the air in the closet. Some telecommunications rooms
are pretty good-sized rooms with their own HVAC (heating, ventilation, and air conditioning)
controls.

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what are Power Requirements

With all of these devices in the wiring closet, it stands to reason that you are going to need some
power receptacles there. Telecommunications rooms have some unique power requirements.
First of all, each of the many small electronic devices will need power, and a single-duplex outlet
will not have enough outlets. Additionally, these devices should all be on an electrical circuit dedicated
to that wiring closet and separate from the rest of the building. And, in some cases, devices
within the same room may require their own circuit, separate from other devices in that room .
The circuit should have its own isolated ground. An isolated ground in commercial wiring is a
ground wire for the particular isolated outlet that is run in the same conduit as the electricalsupply
connectors. This ground is called isolated because it is not tied into the grounding of the
conduit at all. The wire runs from the receptacle back to the point where the grounds and neutrals
are tied together in the circuit panel. You can identify isolated-ground outlets in a commercial
building because they are orange with a small green triangle on them.

The wiring closet should be equipped with a minimum of two dedicated three-wire 120-volt
AC duplex outlets, each on its own 20-amp circuit, for network and system-equipment power.
In addition, separate 120-volt AC duplex outlets should be provided as convenience outlets for
tools, test equipment, etc. Convenience outlets should be a minimum of six inches off the floor
and placed at six-foot intervals around the perimeter of the room. None of the outlets shall be
switched, i.e., controlled by a wall switch or other device that might accidentally interrupt
power to the system.

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How to do Telephone Wiring

LAN wiring components found in the telecommunications room, you will
usually also find all of the wiring for the telephone system, because the two are interrelated. In
most companies, a computer and a telephone are on every desk. Software programs are even
available that can connect the two technologies and allow you to receive all of your voicemails
as e-mails. These programs integrate with your current e-mail system to provide integrated
messaging services (a technology known as unified messaging).
The telephone cables from the individual telephones will come into the telecommunications
room in approximately the same location as the data cables. They will then be terminated in
some kind of patch panel (cross-connect). In many older installations, the individual wires will
be punched down in 66-blocks, a type of punch-down block that uses small “fingers” of metalto connect different UTP wires together. The wires on one side of the 66-block are from the
individual wires in the cables for the telephone system. Newer installations use a type of crossconnect
known as a 110-block. Although it looks different than a 66-block, it functions the
same way. Instead of using punch-down blocks, it is also possible to use the same type of patch
panel as is used for the UTP data cabling for the telephone cross-connect. As with the data
cabling, that option enhances the flexibility of your cabling system.
The wires on the other side of the block usually come from the telephone PBX. The PBX
controls all the incoming and outgoing calls as well as which pair of wires is for which telephone
extension. The PBX has connectors on the back that allow 25 telephone pairs to be connected
to a single 66-block at a time using a single 50-pin connector
The number of 66-blocks is as many as required to support the number
of cables required for the number of telephones in the telephone system.

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How to do LAN Wiring

The first item inside a telecommunications room that will draw your attention is the large bundle
of cables coming into the closet. The bundle contains the cables that run from the closet to the
individual stations and may also contain cables that run from the room to other rooms or closets
in the building. The bundle of cables is usually bound together with straps and leads the LAN
cables to a patch panel, which connects the individual wires within a particular cable to network
ports on the front of the panel. These ports can then be connected to the network equipment
(hubs, switches, routers, and so on), or two ports can be connected together with a patch cable
Some are
mounted on a wall and are known as surface-mount patch panels (also called punch-down blocks).
Others are mounted in a rack and are called rack-mount patch panels. Each type has its own benefits.
Surface-mount panels are cheaper and easier to work with, but they can’t hold as many
cables and ports. Rack-mount panels are more flexible, but they are more expensive. Surfacemount
patch panels make good choices for smaller (less than 50 drops) cabling installations.
Rack-mount patch panels make better choices for larger installations. Patch panels are the
main products used in LAN installations today because they are extremely cost effective and
allow great flexibility when connecting workstations.

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About Television

With the increase in the use of on-demand video technology, it is now commonplace to run
television cable alongside data and telephone cabling. In businesses where local cable access is
possible, television cable will be run into the building and distributed to many areas to provide
cable access. You may be wondering what cable TV has to do with business. The answer is
plenty. News, stock updates, technology access, public-access programs, and, most importantly,
Internet connections can all be delivered through television cable. Additionally, television
cable is used for security cameras in buildings.
Like telephone cable, television cables can share the wiring pathways with their data counterparts.
Television cable typically uses coaxial cable (usually RG-6/U cable) along with F-type, 75-
ohm coaxial connectors. The cables to the various outlets are run back to a central point where
they are connected to a distribution device. This device is usually an unpowered splitter, but it can
also be a powered, complex device known as a television distribution frame. Figure 12.4 shows
how a typical television cabling system might look.

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about Telephone

The oldest (and probably most common) use for a cabling system is to carry telephone signals.
In the old days, pairs of copper wires were strung throughout a building to carry the phone signal
from a central telephone closet to the individual telephone handsets. In the telephone
closet, the individual wires were brought together and mechanically and electrically connected
to all the incoming telephone lines so that the entire building was connected to the outside
world. Surprisingly, the basic layout for a telephone cabling system has changed very little. The
major difference today is that telephone systems have become digital. So most require a private
branch exchange (PBX), a special device that connects all the individual telephones together so
the telephone calls can go out over one high-speed line (called a trunk line) rather than over
multiple individual lines.
Generally speaking, today’s telephone networks are run along the same cabling paths as the
data cabling. Additionally, telephone systems use the same UTP cable that many networks
use for carrying data. They will usually share the same wiring closets with the data and television
cabling. The wires from telephone connections can be terminated almost identically
to data cabling.

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How to Selecting the Right Topology

From a practical standpoint, which topology to use has been decided for you. Because of its
clear-cut advantages, the star topology is the only recognized physical layout in ANSI/TIA/
EIA-568-B. Unless you insist that your installation defy the Standard, this will be the topology
selected by your cabling-system designer.
If you choose not to go with the star topology, the bus topology is usually the most efficient
choice if you’re creating a simple network for a handful of computers in a single room because
it is simple and easy to install. Because MACs are managed better in a star topology, a bus
topology is generally not used in a larger environment. If uptime
is your primary definition of fault resistant (that is, 99 percent uptime, or less than eight hours total downtime per year), you should seriously consider a mesh layout. However, while you are thinking about how fault tolerant a mesh network is, let the word maintenance enter your thoughts. Remember, you will
haven(n - 1)/2 connections to maintain, and this can quickly become a nightmare and exceed your
maintenance budget.
If you decide not to automatically go with a star topology and instead consider all the topologies,
be sure to keep in mind cost, ease of installation, ease of maintenance, and fault tolerance

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