Cabletron Systems 100BASE-FX, Cabling Manual

Page: 89 / 192

Cabling Types 9-3
Token Ring Media
Figure 9-2. Twisted Pair Signal Equalization
STP cable is made up of four or more wires, and each wire within the cable has a
specific insulator color. These colors are part of the IEEE specifications to which
the cable construction process must be held. Each color identifies a particular
usage for the cable. The four standard colors are black, red, green, and orange.
Table 9-1, below, identifies the type of signal that each wire carries.
STP cabling is available in several different arrangements and construction styles,
called Types. The type definitions are based on the IBM cabling system. STP
cabling that may be used in Token Ring environments falls into four types, called
Type 1, Type 2, Type 6, and Type 9. Any of these cable Categories can be used in a
Token Ring installation, provided that the requisite IEEE 802.5 specifications
regarding the cables are met.
Type 1
Type 1 STP consists of two pairs of solid 22 AWG copper strands. Each strand,
approximately 0.02 inch thick, is surrounded by a layer of insulation. The
characteristics of the insulation is determined by the fire resistance construction of
the cable (plenum cable is thicker and made with slightly different material than
normal PVC cabling).
Table 9-1. STP Cable Wire Identifications
Cable Color Application
Black TX -
Red RX +
Green RX -
Orange TX +
Inverted
Transmission
Normal
Transmission
Induced
Noise Spike
Noise spikes
cancel out
Resulting Signal
Reversion of Inverted
Transmission
Original Signal
1845n05