2-2 CHAPTER 2: INSTALLATION AND SETUP
Configuration Rules for Fast Ethernet
The topology rules for 100Mbps Fast Ethernet are
slightly different to those for 10Mbps Ethernet.
Figure 2-1 illustrates the key topology rules and pro-
vides examples of how they allow for large-scale
Fast Ethernet networks.
The key topology rules are:
■Maximum UTP cable length is 100m (328ft) over
category 5 cable.
■A 412m (1352ft) fiber run is allowed for connect-
ing for switch to switch, or endstation to switch,
using half-duplex 100BASE-FX.
■A total network span of 325m (1066ft) is allowed
in single-repeater topologies (one hub stack per
wiring closet with a fiber run to the collapsed
backbone). For example, a 225m (738ft) fiber
downlink from a repeater to a router or switch,
plus a 100m (328ft) UTP run from a repeater out
to the endstations.
Configuration Rules with Full Duplex
The Switch 3000 TX provides full duplex support
for all its fixed ports, and Fast Ethernet Plug-in
Module ports. Full d uplex allows frames to be trans-
mitted and received simultaneously and, in effect,
doubles the potential throughput of a link.
With full duplex, the topology rules are:
■Maximum UTP cable length is 100m (328ft) over
category 5 cable
■A 2km (6562ft) fiber run is allowed for connect-
ing switch to switch, or endstation to switch