FDDI, Fiber Distributed Data Interface

Fiber Optical Connections in LAN

It is a 100 Mbps token-passing, dual-ring media that uses fiber-optical fiber. It is eventually replaced by the Fast Eternet.

Dual-Ring

it uses 2 ring, one is primaray, and the other is secondary, if primary fails, then secindary ring becomes Redundant One.

Constraints to Scale Up

UTP is Unshielded Twisted Pair. This table shows the comparison with Optical Fiber.

  +--------------------+---------------------+-----------------------------+
  |                    |        Fiber        |              UTP            |
  +--------------------+---------------------+-----------------------------+
  | Max Segment Length | 2km between stations|  100m from hub to stations  |
  +--------------------+---------------------+-----------------------------+
  | Max Attach per Seg |         1000        |  2 (hub-hub, or hub-station)|
  +--------------------+---------------------+-----------------------------+
  |Max Network Diameter|         200km       |             200km           |
  +--------------------+---------------------+-----------------------------+