1. Network protocol which converts the data traffic into stream of fixed size cell before transmission.

2. Designed to transfer data simultaneously from multiple sources.

3. Can be employed in both LAN and WAN environments.

4. Can provide a maximum data speed of 622 Mbps.

Version of FDDI
Uses twisted-pair copper cable instead of fiber optic cable
Official name - Twisted-Pair Physical Medium-Dependent (TP-PMD)
Only two types of cables are supported by ANSI standard for CDDI:
STP
UTP

1. Wrapping Process - Modify the structure of the network to recover from failure.

(A)Recovers network connectivity on failure of FDDI station .
(B)Recovers network connectivity on failure of cables between any two FDDI stations.

2. Optical Bypass switch - Maintain the network connectivity by providing an optical connection that bypasses the failed station

1. The connectors used in FDDI are unique .

2. Every FDDI device requires two connectors to support two rings .

3. Using fiber optic cabling, FDDI segments could reach up to two kilometers between systems, with a maximum ring size of 100 kilometers .

1. Single-Attached Concentrator - Connected to the FDDI network through a single connector.

2. Dual-Attached Concentrator - Connected to the FDDI network through A-port and B-port.

1. Single-Attached Station - Connected through a single connector called S-port.

2. Dual-Attached Station - Connected through A-port and B-port .

Provides high performance and multiple stations networking
Widely used in Metropolitan Area network
Based on token ring architecture

1. Uses different types of fiber optic cables for interconnection

2. Types of Fast Ethernet standards which use fiber optic cables:

(A)100BASE-FX - Uses two filaments of multi-mode optical fiber cable. Maximum cable length is 400m.

(B)100BASE-SX - Uses two filaments of multi-mode optical fiber cable. Maximum cable length is 300m

(C)100BASE-BX - Uses single-mode fiber optic cable.

(D)FDDI - Supports 100 Mbps data rate over fiber optic cables.

Defined by IEEE 802.4
Uses bus topology as physical topology
Token passing mechanism is used for data transfer like token ring
Token is passed over a virtual ring within network

Disadvantages:
System collapses if links between nodes are malfunctioning
No alternative link to transmit the data
Data transmission is through single direction
Performance degrades when junk data is transmitted