03-07-2012, 01:40 PM
FIBER DISTRIBUTED DATA INTERFACE
FIBER DISTRIBUTED DATA.ppt (Size: 758.5 KB / Downloads: 29)
Introduction
Shared media network like Ethernet ( IEEE 802.3) & IBM token ring (IEEE 802.5)
100 mbps speed
Runs on optical fiber
American National Standards Institute (ANSI) standard
FDDI Basic Principle
Token ring network like IEEE 802.5
Token: a special sequence of bits
Token circulates around the ring
A station removes the token from ring before transmission
After transmission, the station returns the token to the ring
Collisions are prevented as there is only one token in the ring
FDDI Architectural Model
According to the OSI-RM, FDDI specifies layer 1 (physical layer) and part of layer 2 (data link control layer)
The physical layer handles the transmission of raw bits over a communications link
The data link control (dlc) layer is responsible for maintaining the integrity of information exchanged between two points
The PMD Layer
PMD layer defines the type of media interconnection and its characteristics such as transmitter power, frequencies, receiver sensitivities, bit error rates (per), optical components etc.
PMD-MMF: MultiMode (62.5 micron core diameter) Fiber
PMD-SMF: Single-Mode (8-10 micron core diameter) Fiber
Also defines STP, UTP as media and FDDI on SONET
The PHY layer
Provides the media independent functions associated with the OSI physical layer
Reception: decodes the received bit stream from PMD into a symbol stream for use by the mac layer
Transmission: encodes the data and control symbols provided by mac using 4b/5b encoding for the PMD layer
Also provides SMT the services required for the establishment and maintenance of the FDDI ring (by continuously listening to the incoming signal)
Applications of FDDI
Office automation at the desktop
Backbones for factory automation
Backend data center applications
Campus LAN interconnection
Intercampus Backbones Or Metropolitan Area Networks (mans)
Interconnection of private branch exchanges (pbxs)
Workgroup and departmental LANs
Integrated transport for multimedia applications
FIBER DISTRIBUTED DATA.ppt (Size: 758.5 KB / Downloads: 29)
Introduction
Shared media network like Ethernet ( IEEE 802.3) & IBM token ring (IEEE 802.5)
100 mbps speed
Runs on optical fiber
American National Standards Institute (ANSI) standard
FDDI Basic Principle
Token ring network like IEEE 802.5
Token: a special sequence of bits
Token circulates around the ring
A station removes the token from ring before transmission
After transmission, the station returns the token to the ring
Collisions are prevented as there is only one token in the ring
FDDI Architectural Model
According to the OSI-RM, FDDI specifies layer 1 (physical layer) and part of layer 2 (data link control layer)
The physical layer handles the transmission of raw bits over a communications link
The data link control (dlc) layer is responsible for maintaining the integrity of information exchanged between two points
The PMD Layer
PMD layer defines the type of media interconnection and its characteristics such as transmitter power, frequencies, receiver sensitivities, bit error rates (per), optical components etc.
PMD-MMF: MultiMode (62.5 micron core diameter) Fiber
PMD-SMF: Single-Mode (8-10 micron core diameter) Fiber
Also defines STP, UTP as media and FDDI on SONET
The PHY layer
Provides the media independent functions associated with the OSI physical layer
Reception: decodes the received bit stream from PMD into a symbol stream for use by the mac layer
Transmission: encodes the data and control symbols provided by mac using 4b/5b encoding for the PMD layer
Also provides SMT the services required for the establishment and maintenance of the FDDI ring (by continuously listening to the incoming signal)
Applications of FDDI
Office automation at the desktop
Backbones for factory automation
Backend data center applications
Campus LAN interconnection
Intercampus Backbones Or Metropolitan Area Networks (mans)
Interconnection of private branch exchanges (pbxs)
Workgroup and departmental LANs
Integrated transport for multimedia applications