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1. Network Architecture

2. Token Ring - I
• Token Ring is a network architecture developed by IBM
• Also known as IEEE 802.5
• Uses logical ring topology
• Multiple MAUs can be connected to extend the ring

3. Token Ring - II
• Data transfer is facilitated with the help of token passing
mechanism

4. Token Ring - III
• Speed is either 4 or 16 Mbps
• Performance is significantly faster than Ethernet
networks
• Uses physical star topology
• Hides logical ring inside a hub, known as Multistation
Access Unit (MAU)
• Unshielded Twisted Pair (UTP) or Shielded Twisted Pair
(STP) cables are used connect nodes to the hub

5. Token Ring - IV
• Advantages:  Disadvantages:
– Data collision does not  System collapses if
occur links between nodes
– Every station is allowed are malfunctioning
to transmit data  No alternative link to
– Time required to carry transmit the data
the amount of data can  Data transmission is
be calculated through single direction
– Minimum cable  Performance degrades
requirement when junk data is
transmitted

6. Token Ring Vs Ethernet
Token Ring Ethernet
Token Ring network uses token passing Ethernet network use CSMA/CD
mechanism. mechanism.
Physical star topology is used. Any topology can be used as physical
topology.
Defined by IEEE 802.5 standard. Defined by IEEE 802.3 standard.
Devices in token ring may transmit only at Devices can transmit as soon as the
specific time. medium is free.
Support heavy network traffic and The performance of the Ethernet network
maintains the network performance. degrades as network traffic increases.
Token Ring network is deterministic. Ethernet network is not deterministic as
token ring.
Token ring network provides bandwidth Ethernet network provides bandwidth
efficiency up to 90%. efficiency up to 40%.
The network setup and maintenance of The cost of network equipment is lower for
token ring is expensive than Ethernet. Ethernet.

7. Token Bus
• Defined by IEEE 802.4
• Uses bus topology as physical topology
• Token passing mechanism is used for data transfer like
token ring
• Token is passed over a virtual ring within network

8. Token Ring Vs Token Bus
Token Ring Token Bus
Designed for offices. Designed for large factories.
Star topology is used as physical topology. Bus topology is used as physical topology.
A token is passed over the physical ring A virtual ring is formed over which the token
itself. is passed.
Defined by IEEE 802.5 standard. Defined by IEEE 802.4 standard
In Token ring the maximum time that a In Token Bus network the maximum time
token will take to reach the end station that a token will take to reach the end
can be calculated. station cannot be calculated.

9. Fiber LAN
• Uses different types of fiber optic cables for
interconnection
• Types of Fast Ethernet standards which use fiber optic
cables:
– 100BASE-FX – Uses two filaments of multi-mode optical
fiber cable. Maximum cable length is 400m
– 100BASE-SX – Uses two filaments of multi-mode optical
fiber cable. Maximum cable length is 300m
– 100BASE-BX – Uses single-mode fiber optic cable
– FDDI – Supports 100 Mbps data rate over fiber optic cables

10. Fiber Distributed Data Interface
(FDDI)
• Provides high performance and multiple stations
networking
• Widely used in Metropolitan Area network
• Based on token ring architecture

11. FDDI – Network Model
• FDDI stations:
– Single–Attached Station – Connected through a single
connector called S-port
– Dual–Attached Station – Connected through A-port and B-
port
• FDDI concentrators:
– Single–Attached Concentrator – Connected to the FDDI
network through a single connector
– Dual–Attached Concentrator – Connected to the FDDI
network through A-port and B-port

12. FDDI – Devices
• The connectors used in FDDI
are unique
• Every FDDI device requires two
connectors to support two
rings
• Using fiber optic cabling, FDDI
segments could reach up to
two kilometers between
systems, with a maximum ring
size of 100 kilometers

13. FDDI – Failure Recovery
• Wrapping Process – Modify the structure of the network
to recover from failure
– Recovers network connectivity on failure of FDDI
station
– Recovers network connectivity on failure of cables
between any two FDDI stations
• Optical Bypass switch – Maintain the network
connectivity by providing an optical connection that
bypasses the failed station

14. Copper Distributed Data Interface (CDDI)
• Version of FDDI
• Uses twisted-pair copper cable instead of fiber optic
cable
• Supports 100 Mbps DTR and 100m segment length
• Official name - Twisted-Pair Physical Medium-Dependent
(TP-PMD)
• Only two types of cables are supported by ANSI standard
for CDDI:
– 150 Ohm STP
– CAT5 UTP

15. Signaling and Connection Standards
• Ensure that equipments to be used for creating networks can
work together
Signaling
Standards
FDDI FOIRL 10Base - F

16. Asynchronous Transfer Mode (ATM)
• Network protocol which converts the data traffic into
stream of fixed size cell before transmission
• Designed to transfer data simultaneously from multiple
sources
• Can be employed in both LAN and WAN environments
• Can provide a maximum data speed of 622 Mbps
• A high speed transfer technology for voice, video and
data over public networks

17. ATM – Protocol Reference Model
• ATM protocol reference model describes the
functions of different types of layers and
organizational units that act on data when it is
transmitted using ATM technology.

18. ATM – Performance
• Throughput – Rate at which ATM cells depart from the ATM
switch
• Connection Blocking Probability – Defines the probability of
Non-availability of enough resources for generating physical
connections between inlet and outlet
• Cell Loss Probability – Defines a no. of data cell that can be
handled by a switch queue
• Switching Delay – Time required for cell to pass through the
ATM switch
• Cell Delay Variation – Probability that the switching delay of
the ATM switch exceeds the certain value

19. AppleTalk
• AppleTalk protocol suite was developed by Apple
Computers for use on Macintosh computers
• Developed to allow the multiple users to share resources
• AppleTalk protocol suite is also compatible with Ethernet,
Token Ring and FDDI network architectures
• AppleTalk is an early implementation of distributed
client-server networking system

20. AppleTalk – Network Components
• Sockets – Location in AppleTalk node which is recognized
by a unique address
• Nodes – Device which is a part of an AppleTalk network
e.g. computer, printer or router
• Networks – Consists of a cable with multiple nodes
connected to the cable
• Zones – Constitutes a group of nodes and network which
are logically associated

21. AppleTalk – Network Address
• AppleTalk uses addressing to identify and recognize every
device on a network similar to other common protocols
• Address is broadcast to all other nodes to determine
whether it has been already utilized
• Fields in AppleTalk network address:
– Network number
– Node number
– Socket number

22. LocalTalk
• LocalTalk is obsolete but its relation to Appletalk, a
popular piece of networking software is found on every
Apple brand computer
• Supported by AppleTalk network protocol for Macintosh
computers
• Implemented at the data link-layer
• Uses network bus topology
• Cost effective solutionfor connecting local workgroups
• Allows 32 active nodes within 300m area

23. ARCNET
• Attached Resource Computer NETwork (ARCNET)
• First LAN system introduced by Datapoint Corporation
• Uses a Token Passing bus structure similar to Token Ring
• 255 nodes per network and supports speed up to 20
Mbps
• Supports segment length up to 600 meters
• Still it is popular in robotics and industrial controls
markets

24. ARCNET – Devices
• Active Hub – Collection of 8 or 16 ports and use BNC
female connectors for connecting devices. Isolates the
port electrically
• Passive Hub – Splits signals and consists of 4 ports
• ARCNET Card - Different types of network interface card
(NIC) can be used depending upon the type of network
topology
• BNC Terminator – Prevent signal reflection in network

25. ARCNET - Cables
• Coaxial Cable – Uses RG62 coaxial cable
• Unshielded Twisted Pair (UTP) – Uses RJ11 or RJ45
connectors and maximum segment length is 400m
• Fiber Optic – Uses both SM and MM fibre cable

26. MAN
• MAN connects different LANs
• Cover large distances to function across city
MAN Systems
Switched
Distributed
Multimegabit
Queue
Data
Dual Bus (DQDB)
Service (SMDS)

27. Switched Multimegabit Data Service (SMDS)
• High speed packet-switched MAN technology used for
communication over public data networks (PDNs)
• SMDS is the first broadband service that was provided to
the public
• Packets transferred are of variable length and contains
the source and destination address
• Standard speed is 45 Mbps
• Uses a connectionless service and less expensive as
compared to leased line

28. SMDS Network Components
• Provide high-speed data transmission service
Network
Components
Customer Subscriber
Premises Carrier Network
Equipment Equipment Interface
(CPE) (SNI)

29. IEEE 802.6 Standard
• Mainly developed for MANs
• Uses the Distributed Queue Dual Bus (DQDB) network
form
• DQDB is Data-link layer communication protocol
• Used for data, voice and video transmission based on cell
switching technology
• DQDB can cover distance up to 30 miles and supports
transfer rate ranging from 34 Mbps to 154 Mbps
• DQDB consists of two unidirectional buses

30. Alternatives to Ethernet
• Sometimes it is impossible to run Ethernet cabling so “no
new wire” networking technologies can be used
• In alternatives to Ethernet two or more computers can
be connected into a LAN without running a wire
• Three networking technologies are:
– Wireless LANs
– Phone line networks
– Power line networks

31. Wireless LANs
• Wireless networks enable the user to move around the
house and use the computer.

32. Phone Line Networks - I
• Phone line networks provide satisfactory performance
at a much lower cost than wireless systems.

33. Phone Line Networks II
• Carries data at the rate of 1 or 10 Mbps
• Intel’s AnyPoint are used in this network
• Computers are interconnected through
parallel port

34. Power Line Networks
• Power Line Networks are attached to the PC through
parallel port and by using existing wiring to carry
networking data
• Use radio signals which are easily affected by
interference
• Offer performance of 350 Kbps