FDDI Network: the working and components of FDDI

FDDI abbreviation of (Fiber Distributed Data Interface).

 Definition: A set of ANSI protocols for sending digital data over fiber optic cable. FDDI networks are token-passing networks, and support data rates of up to 100 Mbps (100 million bits) per second. FDDI networks are typically used as backbones for wide-area networks.

Working:

In FDDI passing a token ring scheme is applied. It may have several frames simultaneously circulating on the network. The sender send multiple frames rather than waiting for first one to circulating all the wave around the ring before sending the next frame.

Dual counter rotating ring.

Another feature of FDDI that makes it more complex than token ring is that it uses two counter ring rotate since there is no central device for detecting the network failure. Therefore, another method must be used to ensure that a single failure does not take down the whole network.

FDDI does this by implementing two link in each device one for primary ring another for secondary ring.

 Secondary ring:

An internal or secondary ring can also be used for transmit data. It is useful security when the outer or primary ring when the is not able to transmit data to the destination due to some failure. The some job can be done by the inner ring. The data in the internal ring flow in the opposite direction for example, if an outer or primary ring the data is flowing in clockwise direction then in the inner or secondary ring the data flow is the anticlockwise direction so that it might not face the same problem of failure.

Components of FDDI:

1.       FDDI Network Interface Card.

2.     Fiber Optic FDDI Network Interface Card.

 Two types of FDDI Network Interface Card.

v Dual attachment station.

In it there are two cables attachment points “A&b” called medium interface connector.

“A” is defined as input path for primary ring and output path of secondary ring.

“B” is defined as output path of primary ring and input pat of secondary ring.

v Single Attachment station.

It has only one medium interface connector.

Fiber Optic FDDI Network Interface Card.

Dual and single are linked together in a ring by fiber optic cable.