l a crimping tool, for pressing the cable and
connector together, and
l a die for the specified cable/connection pair, to
make sure cable and connector fit properly.
Installation tool kits that include the crimping tool,
die, cable, connectors, and cable ties can be purchased
from manufacturers. These kits range in price from one
or two hundred to several thousand dollars.
TOOLS FOR TESTING CABLES. Voltmeters
and ammeters provide readings of voltage and current,
or amperage by tapping into the circuit and recording
the electrical activity as it occurs. These recorded values
may or may not provide the details about what is
happening along the lines of the network.
Scanners are much more sophisticated testing tools.
Some of the capabilities of scanners include the
Check for faults in a cable.
Test a cables compliance with network
Monitor performance and electrical activity,
given the type of cable and architecture
Test the cables wiring sequence.
Generate and print a summary of the information
obtained from the tests.
A powerful scanner can test for cable quality, for the
quality of the connections between cable segments, or
between cable and device. A less poweful scanner will
be able to test for noise, crosstalk, signal attenuation,
resistance, cable length, and so on.
Diagnostic software can be used to help anticipate
or catch problems early and to help deal with the
problems once they have arisen. Network versions of
diagnostic software may be expensive, but they can
save the system under some circumstances. For
example, virus detection software can save hours of
reconstruction and reloading the system. Using
software to test the hard disk can identify bad disk
sectors before data can be written to them and move any
data from bad sectors to a safe location.
Another use of diagnostic software is performance
monitoring and analysis, which involves tracking the
networks behavior. This will help to identify
inefficiencies and bottlenecks, so they can be
elimated. While monitoring the systems
performance, keep careful track of the following:
Threats to security
Track these areas especially during the first few
weeks after the network is installed. Do not be surprised
if some of these measured indicators change drastically
during this period. For example, costs may drop
drastically after the startup period, while user
satisfaction and productivity may rise after the initial
problems are resolved.
NETWORK PHYSICAL CONNECTIONS
A network connection is a linkage between network
elements. Physical connections concern the cables and
connectors used to create the physical layout of the
network. When building a network, you must first
establish the physical connections.
Backbone cable refers to the cable that forms the
main trunk, or backbone, of a network. Individual
nodes and other devices may be connected to this cable
using special adapters and a separate stretch of cable.
Backbone cable is defined by the Electronics
Industries Association/Telecommunications Industry
Association-568 (EIA/TIA-568) committee as any
behind the scenes cable; that is, cable running behind
walls, in shafts, or under the ground.
The EIA/TIA-568 recognizes four types of
backbone cable; they are listed in table 2-3.
The use of a backbone network to tie together a
number of small access networks offers several
advantages over the construction of a single large LAN.
The various LANs connected to the backbone are able
to operate in parallel, providing greater processing
efficiency. The multiple-network approach is also more
reliable, since each individual LAN can continue
operating if one of the access networks, or even the
backbone, fails. The backbone network must also be
highly reliable, since the greater distances covered may
make it difficult to locate and repair faults. The LANs
that connect to the backbone must be flexible and low-
cost in terms of installation and user connection.