Specifications

Ethernet Network Design 7-11
Fiber Optic Ethernet Network Design
Grounding and Insulation
When cascading multi-port repeaters be careful to avoid the creation of
ground loops (or multiple paths to ground). If two multi-port repeaters
that perform internal grounding are connected using the BNC ports, a
ground loop will result (see Figure 7-10). In other words, if one repeater is
connected using a BNC port, the other must be connected using the AUI
port.
Figure 7-10. Multi-port Repeater Connection
Fiber Optic Ethernet Network Design
Communication over fiber optics is done with pulses of light transmitted
on glass instead of pulses of electricity transmitted on copper. Because of
the low loss and high noise immunity of fiber, it is the media of choice
when designing an extended distance LAN. A fiber optic segment can be
up to 5 km in length and is used as a point-to-point media where no taps
or branches are allowed.
Fiber optics is typically used in Ethernet networks to connect repeaters
between buildings and to traverse long distances as an IRL. It can also be
used with transceivers or fiber optic network interface cards to connect
network nodes.
A completely fiber optic network may be built as long as the 4 repeater, 5
segment and 1,024 devices rules are not broken. To connect multiple fiber
optic cable runs, a fiber optic multi-port repeater is used. Fiber is used as
an IRL to span between repeaters and multiple fiber drops to workstations
can be implemented (see Figure 7-11).
ST-500 with Lanview
Improper Connection:
Causes Ground Loops
Proper Connection
1913-27