Submitted by:Guided by:Arun Kumar GuptaMr. Vipin KaushikM.Tech (Opto-Electronics)- II SemDept. of Applied Physics SGSITS, Indore

FIBER DISTRIBUTED DATA INTERFACE FDDI

Plan of talkHistory & Development Introduction FDDI Features Working of FDDIFDDI TypesFrame FormatApplications of FDDIAdvantagesFuture of FDDIConclusion *

History & Development FDDI was considered an attractive campus backbone technology in the early to mid 1990s since existing Ethernet networks only offered 10Mbit/s transfer speeds and Token Ring networks only offered 4Mbit/s or 16Mbit/s speeds. Thus it was the preferred choice of that era for a high-speed backbone, but FDDI has since been effectively obsoleted by fast Ethernet which offered the same 100Mbit/s speeds, but at a much lower cost and, since 1998, by Gigabit Ethernet due to its speed, and even lower cost, and ubiquity. *

Introduction FDDI LAN standards were developed by subcommittee X3T9.5 of ANSI (American National Standard Institute) A networking technology that uses a dual ring topology often with dual networking equipment (concentrators, etc.) FDDI facilitates redundancy and protection of the network. If a device fails, the primary and secondary rings enter a "wrap" state to form a logical connection and thus maintain the logical ring in the event of a link failure. FDDI is capable of data rates of 100 Mbps over fiber optic cable (SMF and MMF).*

FDDI FeaturesCan be implemented over copper (CDDI)The fiber optic cables have clear advantages over the copper cables. There is more security, and the fiber optic cables are more reliable than any other wire available. The data transfer in the fiber optic cable takes place without any electrical signals being transmitted. The data flow is undeterred and constant through a fiber optic cable.Long distances can be covered for data flow using the fiber optic cable using a single node. Maximum of 500 stationsMedia access - Token passingSpeed - 100MbpsFrame Size is large as compared to Ethernet i.e. 4500 bytes

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Working of FDDIThe inside architecture of the FDDI is based on the dual rings where the data is flowing in the opposite directions. There are two levels of rings the primary and the secondary. Most of the data transmission takes place using the primary ring and the secondary is idle. However in case the primary does not work the secondary takes over the primarys functionalitiesIt also use optical bypass switch for avoiding the wrap*

Wrap condition*

Cont*

Optical Bypass Switch

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FDDI DAS Ports Attach to the Primary and Secondary Rings

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Function of Concentrator

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FDDI TYPES There are two types of fiber distributed data interface mainly.

The Single Mode Interface The single mode uses the laser technology to generate the light rays.

The Multi Mode Interface. The Multimode fiber uses the LED display to generate the light rays. *

ContThe difference in both these methods is that multi mode as the name suggests allows many rays at one single point of time to pass and the single mode laser allows one ray at one time to pass through.The angles at which the light reflects on the cable are all different so by the time they reach the nodes the time at which they arrive is different. In a single mode there is no such confusion so the data arrives at the node in a streamlined fashion. The methodology which the multi mode uses is called modal dispersion and it is used in an environment which has limited boundaries. In comparison with the multi node the single node will be able to carry more data and deliver at a higher speed along with covering larger distances.

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Maximum Distance1300nm LED on Multimode fiber50/125 500 Mhz per Km 1.9 miles62.5/125 500 Mhz per Km 2.9 miles85/125 300 Mhz per Km 1.5 miles100/140 200 Mhz per Km 1 mile

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Cont.

1300nm Laser on Multimode fiber50/125 1,400 Mhz per Km 16.3 miles62.5/125 1,400 Mhz per Km 16.3 miles85/125 400 Mhz per Km 1.8 miles100/140 600 Mhz per Km 2.7 miles1300nm Laser on Single Mode fiber8/125 100,000 Hhz per Km 29.8 miles

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FDDI frame format*

Applications of FDDIFDDI is used mainly in mission critical and high traffic networks where large amounts of data flow need to flow quickly and efficientlyFDDI is used anywhere that utilizes a large network in need of high bandwidth. Businesses, the Government, hospitals and other medical fields, stock exchanges and money markets etc.*

AdvantagesHigher Capacity and Performance than older LANsMore Simultaneous TransactionsHigher Availability (dual ring topology)Predetermined Performance (adding users have minimal impact on throughput)Longer Distance Loops (2 kilometers to 100 kilometer)*

Future of FDDIA newer version of FDDI, called FDDI-2, supports the transmission of audio and visual information as well as data.Another version, FDDI-Full Duplex Technology or FFDT, uses the same network setup as FDDI but can support twice the data rate, or 200 Mbps. *

ConclusionAfter the advent of FDDI internet has advanced to a great extent even with common day to day users. The internet service providers are able to provide better services to the people and are able to facilitate internet in a better fashion. Since internet has advanced and the number of users has increased, more and more businesses have started e-commerce applications on the internet. Because the fiber distributed data interface is a safe and secure medium when it comes to cables the ecommerce transactions have found a reliable media. FDDI through single node transfers are widely adapted by MNCs for communication between different branches.

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Referenceshttp://www.etutes.com/lesson4/networking_fundamentals_lesson4_7.htmhttp://wiki.cisco.com/wiki/Fiber_Distributed_Data_Interface#Figure:_The_FDDI_Frame_Is_Similar_to_That_of_a_Token_Ring_Framehttp://www.laynetworks.com/FDDI.htmhttp://www.arcelect.com/fddi.htmhttp://en.wikipedia.org/wiki/Fiber_Distributed_Data_InterfaceForging FDDI - Selected Areas in Communications, IEEE Journal by FE Ross - 2002John M.Senior,second edition,page no.885

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Thank You!*