Fiber Distributed Data Interface


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Fiber Distributed Data Interface

(FDDI) A 100 Mbit/s ANSI standard local area network architecture, defined in X3T9.5. The underlying medium is optical fibre (though it can be copper cable, in which case it may be called CDDI) and the topology is a dual-attached, counter-rotating token ring.

FDDI rings are normally constructed in the form of a "dual ring of trees". A small number of devices, typically infrastructure devices such as routers and concentrators rather than host computers, are connected to both rings - these are referred to as "dual-attached". Host computers are then connected as single-attached devices to the routers or concentrators. The dual ring in its most degenerate form is simply collapsed into a single device. In any case, the whole dual ring is typically contained within a computer room.

This network topology is required because the dual ring actually passes through each connected device and requires each such device to remain continuously operational (the standard actually allows for optical bypasses but these are considered to be unreliable and error-prone). Devices such as workstations and minicomputers that may not be under the control of the network managers are not suitable for connection to the dual ring.

As an alternative to a dual-attached connection, the same degree of resilience is available to a workstation through a dual-homed connection which is made simultaneously to two separate devices in the same FDDI ring. One of the connections becomes active while the other one is automatically blocked. If the first connection fails, the backup link takes over with no perceptible delay.

Usenet newsgroup: news:comp.dcom.lans.fddi.
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During the next two years, the company plans to unveil several LAN products that conform to the Fiber Distributed Data Interface standard.
The total solution uses a variety of networking technologies, including switched Gigabit Ethernet, switched Fast Ethernet, switched Fiber Distributed Data Interface (FDDI) and Integrated Services Digital Network (ISDN).
The SkyNet 600 Series provides full-speed 100 Mbps connectivity for Fiber Distributed Data Interface (FDDI) networks at distances up to 2.
NPI; NASDAQ:NPIX), headquartered in Milpitas, California, supplies a full range of Layer 2/Layer 3 Gigabit Ethernet switches and Fiber Distributed Data Interface (FDDI) switches and hubs on an OEM basis to other industry-leading manufacturers.
It supports 4B/5B and 5B/6B, TAXIchip, and Fiber Distributed Data Interface (FDDI) encoding standards.
SkyNet 600 Series offering 100 Mbps Fiber Distributed Data Interface (FDDI) network connectivity at distances up to 2.
NPI; Nasdaq:NPIX), headquartered in Milpitas, supplies a full range of Layer 2/3 Gigabit Ethernet switches and Fiber Distributed Data Interface (FDDI) switches and hubs on an OEM basis to other industry-leading manufacturers.