FDDI AND TOKEN Ring

1. Students understand network cables
types and features of each one .
• 5 min Act1 Warm up motivating video
• 5 min Act2 Essential question brain storm
• 15 min Act3 Introduction teacher demonstrate about cables
• 10 min Act4 – TPS Searching about network access types
• 10 min Act5 – listen to an animated video about FDDI
and then asking questions.
• 10 min Act6 - Teacher demonstrate “FDDI 11”
• 10 min Act7 – brain storm “Q and A about FDDI ”
• 5 min Act8 - Closing the session with a summery !.
• 10 min Act8 Reflection
• Home work
1

2. Classroom Norms
Osama Ghandour Geris
Assiut STEM
School
2
Take
notes in a
paper

3. Warm up
5 Min motivating
video
Press here for on
line
Press here for off
lineOR

4. Essential Questions
• What are FDDI and TOKEN RING
• How to select a suitable network access
between FDDI , TOKEN RING and
EATHERNET networks for
mentioned specifications or design
requirements ?
• Why use FDDI network ?
• What are the FDDI BENEFITS ?
Brain Storm
5 min

5. Now set in groups
During the next PPT
• Take note as
groups and I’ll
pick one
answer from
each group
One in desktop presents
MARCH 6, 2003 FDDI 5
One takes picture
One is observer COS I will take his comments in the end of the session

6. Networks: Token Ring and FDDI 6
IEEE 802.5 and Token Ring
• Proposed in 1969 and initially referred to as a
Newhall ring.
Token ring :: a number of stations connected by
transmission links in a ring topology.
Information flows in one direction along the
ring from source to destination and back to
source.
Medium access control is provided by a small
frame, the token, that circulates around the
ring when all stations are idle. Only the station
possessing the token is allowed to transmit at any
given time.

7. Networks: Token Ring and FDDI 7
Token Ring Operation
• When a station wishes to transmit, it must wait
for token to pass by and seize the token.
– One approach: change one bit in token which
transforms it into a “start-of-frame sequence” and
appends frame for transmission.
– Second approach: station claims token by removing
it from the ring.
• Frame circles the ring and is removed by the
transmitting station.
• Each station interrogates passing frame, if
destined for station, it copies the frame into
local buffer. {Normally, there is a one bit delay as
the frame passes through a station.}

8. Networks: Token Ring and FDDI 8
Wiring center
A
B
C
D
E
Figure 6.58Leon-Garcia & Widjaja: Communication NetworksCopyright ©2000 The McGraw Hill Companies
Token Ring Network
with star topology

9. Networks: Token Ring and FDDI 9
Re-inserting token on the ring
Choices:
1. After station has completed
transmission of the frame.
2. After leading edge of transmitted
frame has returned to the sending
station
The essential issue is whether more than
one frame is allowed on the ring at the
same time.

10. Networks: Token Ring and FDDI 10
IEEE 802.5 Token Ring
• 4 and 16 Mbps using twisted-pair cabling
with differential Manchester line encoding.
• Maximum number of stations is 250.
• Waits for last byte of frame to arrive before
reinserting token on ring {new token after
received}.
• 8 priority levels provided via two 3-bit fields
(priority and reservation) in data and token
frames.
• Permits 16-bit and 48-bit addresses (same
as 802.3).

11. Networks: Token Ring and FDDI 11
Token Ring
• Under light load – delay is added due to
waiting for the token.
• Under heavy load – ring is “round-robin”
• The ring must be long enough to hold the
complete token.
• Advantages – fair access
• Disadvantages – ring is single point of failure,
added issues due to token maintenance.

12. Networks: Token Ring and FDDI 12
Token Maintenance Issues
What can go wrong?
• Loss of token (no token circulating)
• Duplication of token (forgeries or mistakes)
The need to designate one station as the
active ring monitor.
• Persistently circulating frame
• Deal with active monitor going down.

13. MARCH 6, 2003 FDDI 13

14. Data link layer Layer2

15. Networks: Token Ring and FDDI 15
SD
Destination
Address
Source
Address
Information FCS
1 4
EDFC
2 or 6 2 or 61 1
AC
1
FS
1
SD AC EDToken Frame Format
P P P T M R R R
Access
control
PPP Priority; T Token bit
M Monitor bit; RRR Reservation
Frame
control
FF frame type
ZZZZZZ control bitF F Z Z Z Z Z Z
Ending
delimiter
I intermediate-frame bit
E error-detection bit
Frame
status
A address-recognized
bit
xx undefined
C frame-copied bit
I EJ K 1 J K 1
A C x x A C x x
Data Frame Format
Starting
delimiter
J, K non-data symbols (line code)0 0J K 0 J K 0
Figure 6.61Leon-Garcia & Widjaja: Communication NetworksCopyright ©2000 The McGraw Hill Companies
IEEE 802.5 Token and data frame structure

16. FDDI 16
5 min
listen to an animated
video about Token Ring
Press here for on
line
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17. FIBER DISTRIBUTED DATA
INTERFACE (FDDI)
ADNAN MASOOD
ECE DEPT
EMAIL: AM98@DREXEL.EDU
15
m
in

18. MARCH 6, 2003 FDDI 18
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

19. MARCH 6, 2003 FDDI 19
TIMELINE FOR FDDI
Fiber Distributed Data Interface
• 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

20. MARCH 6, 2003 FDDI 20
TOKEN RING NETWORK

21. MARCH 6, 2003 FDDI 21
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

22. MARCH 6, 2003 FDDI 22
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
200 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

23. MARCH 6, 2003 FDDI 23
FDDI DUAL RINGS
FDDI DUAL RING ARCHITECTURE

24. MARCH 6, 2003 FDDI 24
OPERATION ON FAILURE OF THE PRIMARY RING

25. MARCH 6, 2003 FDDI 25
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

26. MARCH 6, 2003 FDDI 26

27. MARCH 6, 2003 FDDI 27
RELATIONSHIP BETWEEN FDDI AND OSI-RM

28. MARCH 6, 2003 FDDI 28
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

29. MARCH 6, 2003 FDDI 29
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)

30. MARCH 6, 2003 FDDI 30
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

31. MARCH 6, 2003 FDDI 31
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

32. Data link layer Layer2

33. Networks: Token Ring and FDDI 33
SD
Destination
Address
Source
Address
Information FCS
8 4
EDFC
2 or 6 2 or 61 11
FS
1
PRE
Preamble
SD FC EDToken Frame Format PRE
Frame
Control
Data Frame Format
CLFFZZZZ C = Synch/Asynch
L = Address length (16 or 48 bits)
FF = LLC/MAC control/reserved frame type
Figure 6.63
Leon-Garcia & Widjaja: Communication Networks
FDDI frame structure

34. How could to know more
about FDDI network ? 10
min
• Example Movie
Ask or call a
college
Ask a
teacher Ask or call an
expert or an
engineer
Search through search
engine such as google
or Bing for ppt or pdf
files using your laptop
or smart phone through
internet connection
Search through
YouTube
Search through wiki
Beddia
Osama Ghandour Geris
Assiut
34

35. FDDI 35
5 min
listen to an animated
video about FDDI
Press here for on
line
Press here for off
lineOR

36. MARCH 6, 2003 FDDI 36
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

37. MARCH 6, 2003 FDDI 37
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 802.3 AND IEEE 802.5

38. MARCH 6, 2003 FDDI 38
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

39. MARCH 6, 2003 FDDI 39
A FDDI BACKBONE NETWORK EXAMPLE

40. brain storm “Q and A about FDDI ”
• Practical Network Systems
Work in a group of 3/4 students , Write
in a paper What are the tools , devices ,
cables and information which a network
engineer should has for installing a
FDDI network ? 10 min
10 min

41. Closing the session with a
summery !
Note.all students
should install the
packet tracer network
software application
5 min

42. MARCH 6, 2003 FDDI 42
COMPARISON OF TRANSMISSION MEDIA

43. Networks: Token Ring and FDDI 43
Differences between 802.5 and FDDI
Token Ring
• Shielded twisted pair
• 4, 16 Mbps
• No reliability specified
• Differential Manchester
• Centralized clock
• Priority and Reservation
bits
• New token after receive
FDDI
• Optical Fiber
• 100 Mbps
• Reliability specified (dual ring)
• 4B/5B encoding
• Distributed clocking
• Timed Token Rotation Time
• token after transmit

44. MARCH 6, 2003 FDDI 44
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)
2.5 KM 300 M
(RECOMMENDED
100 M)

45. MARCH 6, 2003 FDDI 45
REFERENCES
• SONU MIRCHANDANI & RAMAN KHANNA (EDITORS), FDDI
TECHNOLOGY AND APPLICATIONS, CHAPTERS 1,2,3,6,13,
JOHN WILEY & SONS, INC., 1992
• AMIT SHAH & G. RAMAKRISHNAN, FDDI: A HIGH SPEED
NETWORK, PTR PRENTICE HALL, 1994
• BERNHARD ALBERT & ANURA P. JAYASUMANA, FDDI AND
FDDI-II - ARCHITECTURE PROTOCOLS, AND
PERFORMANCE, ARTECH HOUSE, 1994
• LARRY L. PETERSON & BRUCE S. DAVIE, COMPUTER
NETWORKS: A SYSTEMS APPROACH, MORGAN
KAUFMANN, 2000
• HTTP://WWW.IOL.UNH.EDU/TRAINING/FDDI/HTMLS/
• HTTP://WWW.CISCO.COM/UNIVERCD/CC/TD/DOC/CISINTWK/
ITO_DOC/FDDI.HTM#XTOCID14
• HTTP://WWW2.RAD.COM/NETWORKS/1995/FDDI/FDDI.HTM

46. CCNA
Certified Computer Network Administrator
This Certificate from Cisco company
free on line certificate from www.netacade.com
Osama Ghandour Geris
Assiut STEM
School

47. Osama Ghandour Geris
Assiut
47
Do your best ,
engage , have
a good
attitude ,
present and
practice in
Computer
Lab. to win
this
certificate.

48. 5 min Reflection
• What is your goal to accomplish in
next week End Using FDDI
network? Think out of the box
such as creating a game or
animated video for describing
FDDI !
Osama Ghandour Geris
Assiut
48

50. 50
biomimicry
computer
network
Osama Ghandour Geris

51. Home work 1
• You studied about network
topologies , network cables and
ways of transferring data how
you can use one of these topics
in your mimicry capstone.
Osama Ghandour Geris
Assiut
51

52. Home work 2
• Create a game or animated
video for describing FDDI ?
• Solve the on line quiz about
network access types and its
features .
Osama Ghandour Geris
Assiut
52

53. Download and Install
packet tracer in your
machine by next session to
gain blue other wise you
will be not rated .
Mr. Osama Ghandour

54. packet tracer
Press here for on
line
Press here for off
line
OR
Video

58. MARCH 6, 2003 FDDI 58

59. https://twitter.com/osamageris
https://www.linkedin.com/in/osamaghandour/
https://www.youtube.com/user/osmgg2
https://www.facebook.com/osama.g.geris
Osama Ghandour Geris
Assiut
59
Find me @
OR find me by clicking @

60. Thank you
Mr. Osama Ghandour