If one of the problems discussed so far isn’t the
cause of your networking quandary, the next logical suspect is the
cabling that connects the workstations. This section discusses cabling,
gives you a few pointers for preventing cable problems, and discusses
some common cable kinks that can crop up.
Although most
large-scale cabling operations are performed by third-party cable
installers, home setups are usually do-it-yourself jobs. You can prevent
some cable problems and simplify your troubleshooting down the road by
taking a few precautions and “ounce of prevention” measures in advance:
First and foremost,
always buy the highest-quality cable you can find (for example,
Category 5e or Category 6 or higher for twisted-pair cable). With
network cabling, you get what you pay for.
Good-quality
cable will be labeled. You should also add your own labels for things
such as the source and destination of the cable.
To
avoid electromagnetic interference, don’t run cable near electronic
devices, power lines, air conditioners, fluorescent lights, motors, and
other electromagnetic sources.
Try to avoid phone lines because the ringer signal can disrupt network data carried over twisted-pair cable.
To avoid the cable being stepped on accidentally, don’t run it under carpet.
To
avoid people tripping over a cable (and possibly damaging the cable
connector, the NIC port, or the person doing the tripping!), avoid
high-traffic areas when laying the cable.
If you plan to run cable outdoors, use conduit or another casing material to prevent moisture damage.
Don’t use excessive force to pull or push a cable into place. Rough handling can cause pinching or even breakage.
If you suspect cabling might be the cause of your network problems, here’s a list of a few things to check:
Watch for electromagnetic interference—
If you see garbage on a workstation screen or experience random packet
loss or temporarily missing nodes, the problem might be electromagnetic
interference. Check your cables to make sure that they are at least 6 to
12 inches from any source of electromagnetic interference.
Check your connections—
Loose connections are a common source of cabling woes. Be sure to check
every cable connection associated with the workstation that’s
experiencing network difficulty, including connections to the network
adapter, router, switch, and so on.
Check the lay of the line— Loops
of cable could be generating an electrical field that interferes with
network communication. Try not to leave your excess cable lying around
in coils or loops.
Inspect the cable for pinching or breaks—
A badly pinched cable can cause a short in the wire, which could lead
to intermittent connection problems. Make sure that no part of the cable
is pinched, especially if the back of the computer is situated near a
wall. A complete lack of connection with the network might mean that the
cable’s copper core has been severed completely and needs to be
replaced.
