Cabletron Systems 42 Switch User Manual


 
General Considerations
Page 2-2
to re-route cabling away from potential noise sources, or to ensure that
the electrical wiring in the area is properly wired and grounded, or to
replace connectors along affected segments.
Temperature
The attenuation of PVC-insulated cable varies significantly with
temperature. Check the cable manufacturer’s specifications. Plenum-
rated cables are strongly recommended in areas where temperatures
exceed 40˚C. Under such conditions, plenum-rated cables ensure that
cable attenuation remains within specifications.
Installation Recommendations
In addition to complying with the cable specifications presented in
Sections 2.2 and 2.3, the cabling installation should comply with the
following recommendations to obtain optimum performance from the
network:
UTP cabling should be free of splices, stubs, or bridged taps.
No more than two punch-down blocks should exist between TCU
ports and wall outlets.
Metal troughs, ducts, etc. carrying Token Ring signals should be
properly grounded.
Cables should be routed away from sources of electrical noise, such as
power lines, fluorescent lights, electric motors, radio interference, and
heavy machinery.
Token Ring signals should not be routed through UTP cables that exit
a building or which are adjacent to cables either exiting a building or
exposed to lightning strikes and power surges.
UTP cables that contain Token Ring signals should not be
simultaneously used for applications which may impress high
voltages (greater than 5 volts) with sharp rise or fall times, since the
noise coupling from such signals could directly cause errors on the
Token Ring network.
For single telecommunications closet rings, lobe lengths should not
exceed 100 meters of 22 to 24 AWG wire from the attaching device and
the TCU port.