FDDI stands for Fiber Distributed Data Interface.
FDDI is a set of ANSI and ISO standards for data transmission on fiber optic lines in a local area network.
In addition to being large geographically, an FDDI local area network can support thousands of users.
FDDI is frequently used on the backbone for a wide area network (WAN).
FDDI provides 100 Mbps of data throughput.
FDDI includes two interfaces.
It is used to connect the equipment to the ring over long distances.
FDDI is a LAN with Station Management.
Allows all stations to have equal amount of time to transmit data.
FDDI Access Method:
The FDDI protocol is based on the token ring protocol.
An FDDI network contains two token rings, one for possible backup in case the primary ring fails.
Any station wants to transmit information holds the token and then transmits the information.
When it finish it release the token in the ring.
The time a station holds the token is called as Synchronous Allocation Time (SAT).
SAT time is variable for each station.
The allocation of this time to each station is achieved by Station Management (SMT).
The function of SMT are Ring Control, Ring Initialization, Station Insertion and Station Removal.