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.
Fiber Optic Hub
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AUI Port |
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Figure 7 Fiber Optic Hub
As mentioned earlier, Ethernet uses
the CSMA/CD access method. As the | Ethernet - Segment A |
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| Ethernet - Segment B | ||||||||||||||||
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number of active stations increases, a |
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point is finally reached where |
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collisions occur frequently and |
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response time begins to suffer |
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(usually around 50% utilization). |
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Bridges are commonly used to |
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| Workstation | ||||||||
alleviate this problem. The network is |
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divided into two segments connected |
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by a bridge. The bridge blocks all |
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transmissions from a segment except |
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| Server | |||||||||||||
those intended for stations on the |
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other side of the bridge. Therefore, | Figure 8 Ethernet Bridge |
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traffic that is local to a segment does |
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not tie up the bandwidth on another |
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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
CTI 2572 Technical Overview Manual
