Figure 7 Fiber Optic Hub; Figure 8 Ethernet Bridge - Control Technology Ethernet TCP/IP Adapter Module CTI 2572 Technical Overview

FOIRL (Fiber Optic)
Like the 10BaseT standard, the fiber optic
cabling scheme uses a hub technology.
Network stations are connected to the hub
via point to point fiber optic connections.
The fiber optic cable is attached to the
network adapter using transceivers
connected to the AUI port. A fiber optic
cable run can extend up to 1 km.
Fiber optics is often used where longer
distances, noise immunity, and lightning
protection are required. This includes
communications within buildings on a
factory campus and as a "backbone" within
a single large building. Except for the
media, fiber optic hubs are essentially
equivalent to 10BaseT hubs.
Bridges.
As mentioned earlier, Ethernet uses
the CSMA/CD access method. As the
number of active stations increases, a
point is finally reached where
collisions occur frequently and
response time begins to suffer
(usually around 50% utilization).
Bridges are commonly used to
alleviate this problem. The network is
divided into two segments connected
by a bridge. The bridge blocks all
transmissions from a segment except
those intended for stations on the
other side of the bridge. Therefore,
traffic that is local to a segment does
not tie up the bandwidth on another
segment. Most bridges can automatically learn which transmissions need to be routed across the
bridge. In addition, bridges can be used to extend the distance of an Ethernet network, since they
perform a repeater function also.
12
Fiber Optic Hub
Transceiver
AUI Port
Station

Figure 7 Fiber Optic Hub

Ethernet - Segment A
Workstation
"Filtered" Packets
Workstation
Server

Figure 8 Ethernet Bridge

Transceiver
Transceiver
AUI Port
Station
Ethernet - Segment B
Bridge
Workstation
Workstation
Server
CTI 2572 Technical Overview Manual
AUI Port
Other Hub