MCSE : Security Specialist
FDDI
Fiber
Distributed Data Interface, shares many of the same features as
token ring, such as a token passing, and the continuous network loop
configuration. But FDDI has better fault tolerance because of its
use of a dual, counter-rotating ring that enables the ring to
reconfigure itself in case of a link failure. FDDI also has higher
transfer speeds, 100 Mbps for FDDI, compared to 4 - 16 Mbps for
Token Ring.
Unlike Token Ring, which uses a star topology, FDDI uses a physical
ring. Each device in the ring attaches to the adjacent device using
a two stranded fiber optic cable. Data travels in one direction on
the outer strand and in the other direction on the inner strand.
When all devices attached to the dual ring are functioning properly,
data travels on only one ring. FDDI transmits data on the second
ring only in the event of a link failure.
|
Media
|
MAC Method
|
Signal Propagation Method
|
Speed
|
Topologies
|
Maximum Connections
|
|
Fiber-optic |
Token passing |
Forwarded from device to device (or port to port on a hub)
in a closed loop |
100 Mbps |
Double ring Star |
500 nodes |
|
