FIBER DISTRIBUTED DATA INTERFACE (FDDI)INTRODUCTIONSEQUENCE OF PRESENTATIONTIMELINE FOR FDDIFDDI BASIC PRINCIPLESlide 6Slide 7FDDI PHYSICAL PROPERTIESFDDI DUAL RINGSSlide 10FDDI ARCHITECTURAL MODELSlide 12THE PMD LAYERTHE PHY LAYERTHE MAC LAYERTHE SMT LAYERFDDI - IISlide 18FDDI BENEFITSSlide 20FDDI LIMITATIONSAPPLICATIONS OF FDDISlide 23COMPARISON WITH OTHER NETWORKSREFERENCESSlide 26FIBER DISTRIBUTED DATA INTERFACE (FDDI)ADNAN MASOODECE DEPTEMAIL: [email protected] 6, 2003 FDDI 2INTRODUCTION•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) STANDARDMARCH 6, 2003 FDDI 3SEQUENCE 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 NETWORKSMARCH 6, 2003 FDDI 4TIMELINE 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 1989MARCH 6, 2003 FDDI 5FDDI 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 RINGMARCH 6, 2003 FDDI 6TOKEN RING NETWORKMARCH 6, 2003 FDDI 7FDDI 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 RINGMARCH 6, 2003 FDDI 8FDDI 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 ENCODINGMARCH 6, 2003 FDDI 9FDDI DUAL RINGSFDDI DUAL RING ARCHITECTUREMARCH 6, 2003 FDDI 10OPERATION ON FAILURE OF THE PRIMARY RINGMARCH 6, 2003 FDDI 11FDDI 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 POINTSMARCH 6, 2003 FDDI 12RELATIONSHIP BETWEEN FDDI AND OSI-RMMARCH 6, 2003 FDDI 13THE 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 SONETMARCH 6, 2003 FDDI 14THE 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)MARCH 6, 2003 FDDI 15THE 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 TOKENMARCH 6, 2003 FDDI 16THE 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 DEVICEMARCH 6, 2003 FDDI 17FDDI - 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 OPERATIONMARCH 6, 2003 FDDI 18FDDI-II STATION ARCHITECTURAL MODELMARCH 6, 2003 FDDI 19FDDI 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 CABLEMARCH 6, 2003 FDDI 20COMPARISON OF TRANSMISSION MEDIAMARCH 6, 2003 FDDI 21FDDI 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 802.3 AND IEEE 802.5MARCH 6, 2003 FDDI 22APPLICATIONS 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