1. FIBER DISTRIBUTED DATA INTERFACE (FDDI)
ADNAN MASOOD
ECE DEPT

2. 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

3. SEQUENCE OF PRESENTATION
INTRODUCTION
TIMELINE FOR DEVELOPMENT OF FDDI
FDDI BASIC PRINCIPLE
FDDI PHYSICAL PROPERTIES
FDDI ARCHITECTURAL MODEL
FDDI - II
BENEFITS & LIMITATIONS
APPLICATIONS
COMPARISON WITH OTHER NETWORKS
MARCH 6, 2003
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4. TIMELINE FOR FDDI
PROJECT INITIATED IN OCTOBER 1982 BY JAMES HAMSTRA AT SPERRY (NOW UNISYS)
TWO PROPOSALS FOR MEDIA ACCESS CONTROL (MAC) & PHYSICAL (PHY) LAYERS SUBMITTED IN JUNE 1983
FDDI MAC BECAME AN ANSI STANDARD IN LATE 1986
FDDI PHY WON ANSI STANDARDIZATION IN 1988
FDDI - II PROPOSAL WAS MADE IN EARLY 1986
FIRST PUBLIC DEMONSTRATIONS AT ADVANCED MICRO DEVICES (AMD) IN 1989
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5. 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
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6. TOKEN RING NETWORK
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7. 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
MARCH 6, 2003
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8. FDDI PHYSICAL PROPERTIES
DUAL-COUNTER-ROTATING TOKEN RING ARCHITECTURE
ONE RING IS PRIMARY AND THE OTHER SECONDARY
UP TO 500 STATIONS WITH A MAXIMUM DISTANCE OF 2 KM BETWEEN ANY PAIR OF STATIONS FOR MULTIMODE FIBER
WITH SINGLE-MODE FIBER THE DISTANCE CAN BE UP TO 40 KM
MAXIMUM RING LENGTH IS 100 KM (TOTAL FIBER LENGTH IS 200 KM FOR TWO RINGS)
USES 4B/5B ENCODING
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9. FDDI DUAL RINGS
FDDI DUAL RING ARCHITECTURE
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10. OPERATION ON FAILURE OF THE PRIMARY RING
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11. 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
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12. RELATIONSHIP BETWEEN FDDI AND OSI-RM
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13. THE PMD LAYER
PMD LAYER DEFINES THE TYPE OF MEDIA INTERCONNECTION AND ITS CHARACTERISTICS SUCH AS TRANSMITTER POWER, FREQUENCIES, RECEIVER SENSITIVITIES, BIT ERROR RATES (BER), 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
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14. 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)
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15. THE MAC LAYER PROVIDES FAIR & DETERMINISTIC ACCESS
FAIR: NO NODE HAS ADVANTAGE OVER ANOTHER IN ACCESSING THE MEDIUM
DETERMINISTIC: UNDER ERROR-FREE CONDITIONS, THE TIME A NODE HAS TO WAIT TO ACCESS THE MEDIUM CAN BE PREDICTED
MEDIUM ACCESS IS CONTROLLED BY A TOKEN
TOKEN PERMITS THE NODE THAT RECEIVES IT TO TRANSMIT FRAMES
THE MAC LAYER OF THE NODE THAT GENERATED THE FRAME IS RESPONSIBLE FOR REMOVING THE TOKEN
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16. THE SMT LAYER
A SOPHISTICATED, BUILT-IN NETWORK MONITORING AND MANAGEMENT CAPABILITY
SMT IS NOT AN OSI-RM SPECIFICATION
MAKING USE OF THE SERVICES PROVIDED BY PMD, PHY, AND MAC, IT CARRIES OUT MANY FUNCTIONS SUCH AS NODE INITIALIZATION, BYPASSING FAULTY NODES, COORDINATION OF NODE INSERTION AND REMOVAL, FAULT ISOLATION AND RECOVERY
SMT IS MOST COMMONLY IMPLEMENTED AS A SOFTWARE PROCESS RUNNING ON THE FDDI DEVICE
MARCH 6, 2003
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17. FDDI - II ENHANCED FDDI THAT HANDLES DATA, VOICE, AND VIDEO
SAME FEATURES AS BASIC FDDI (FDDI - I), INCLUDING MAXIMUM NUMBER OF MODES, 100 MBPS DATA TRANSFER BIT RATE, AND THE DUAL RING
DEFINES THE PHYSICAL LAYER AND THE LOWER HALF OF THE DATA LINK LAYER SIMILAR TO FDDI-I
FDDI-I SUPPORTS ONLY PACKET MODE (SYNCHRONOUS AND ASYNCHRONOUS) TRAFFIC, FDDI-II SUPPORTS BOTH PACKET DATA AS WELL AS ISOCHRONOUS DATA TRAFFIC (IN FDDI ISOCHRONOUS INDICATES A CLASS OF TRAFFIC FOR VOICE AND VIDEO
THE SIMULTANEOUS SUPPORT OF BOTH PACKET AND ISOCHRONOUS TRAFFIC IS CALLED THE HYBRID MODE OF OPERATION
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18. FDDI-II STATION ARCHITECTURAL MODEL
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19. FDDI BENEFITS HIGH BANDWIDTH (10 TIMES MORE THAN ETHERNET)
LARGER DISTANCES BETWEEN FDDI NODES BECAUSE OF VERY LOW ATTENUATION ( 0.3 DB/KM) IN FIBERS
IMPROVED SIGNAL-TO-NOISE RATIO BECAUSE OF NO INTERFERENCE FROM EXTERNAL RADIO FREQUENCIES AND ELECTROMAGNETIC NOISE
BER TYPICAL OF FIBER-OPTIC SYSTEMS (10^-11) IS SUBSTANTIALLY BETTER THAN THAT IN COPPER (10^-5) AND MICROWAVE SYSTEMS (10^-7)
VERY DIFFICULT TO TAP SIGNALS FORM A FIBER CABLE
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20. COMPARISON OF TRANSMISSION MEDIA
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21. FDDI LIMITATIONS
HIGH COST OF OPTICAL COMPONENTS REQUIRED FOR TRANSMISSION/RECEPTION OF SIGNALS (ESPECIALLY FOR SINGLE MODE FIBER NETWORKS)
MORE COMPLEX TO IMPLEMENT THAN EXISTING LOW SPEED LAN TECHNOLOGIES SUCH AS IEEE AND IEEE 802.5
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22. 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
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23. A FDDI BACKBONE NETWORK EXAMPLE
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24. COMPARISON WITH OTHER NETWORKS
FEATURES
FDDI
ETHERNET
TOKEN RING
TRANSMISSION RATE
125 MBAUD
20 MBAUD
8 & 32 MBAUD
DATA RATE
100 MBPS
10 MBPS
4 & 16 MBPS
SIGNAL ENCODING
4B/5B (80% EFFICIENT)
MANCHESTER (50% EFFICIENT)
DIFFERENTIAL MANCHESTER (50% EFFICIENT)
MAXIMUM COVERAGE
100 KM
2.5 KM
CONFIGURATION DEPENDENT
MAXIMUM NODES
500
1024
250
MAXIMUM DISTANCE BETWEEN NODES
2 KM (MULTIMODE FIBER)
40 KM (SINGLE-MODE FIBER)
300 M (RECOMMENDED 100 M)
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