Cabletron Systems 24 User Manual

General ConsiderationsPage 2-2to re-route cabling away from potential noise sources, or to ensure thatthe electrical wiring in the area is properly wired and grounded, or toreplace connectors along affected segments.TemperatureThe attenuation of PVC-insulated cable varies significantly withtemperature. Check the cable manufacturer’s specifications. Plenum-rated cables are strongly recommended in areas where temperaturesexceed 40˚C. Under such conditions, plenum-rated cables ensure thatcable attenuation remains within specifications.Installation RecommendationsIn addition to complying with the cable specifications presented inSections 2.2 and 2.3, the cabling installation should comply with thefollowing recommendations to obtain optimum performance from thenetwork:• UTP cabling should be free of splices, stubs, or bridged taps.• No more than two punch-down blocks should exist between TCUports and wall outlets.• Metal troughs, ducts, etc. carrying Token Ring signals should beproperly grounded.• Cables should be routed away from sources of electrical noise, such aspower lines, fluorescent lights, electric motors, radio interference, andheavy machinery.• Token Ring signals should not be routed through UTP cables that exita building or which are adjacent to cables either exiting a building orexposed to lightning strikes and power surges.• UTP cables that contain Token Ring signals should not besimultaneously used for applications which may impress highvoltages (greater than 5 volts) with sharp rise or fall times, since thenoise coupling from such signals could directly cause errors on theToken Ring network.• For single telecommunications closet rings, lobe lengths should notexceed 100 meters of 22 to 24 AWG wire from the attaching device andthe TCU port.