chapter 6 other network architecture

8/10/2019 Chapter 6 Other Network Architecture

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Chapter 6 1

Other Network

Architecture

Chapter 6


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Chapter 62

Chapter Objectives - I

Explain token ring topology

Explain token bus topology

Differentiate between token ring, token bus and

Ethernet

Explain FDDI Describe signaling and connection standards


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Chapter 63

Chapter Objectives - II

Understand ATM

Explain AppleTalk

Explain ARCNET

Explain MAN systems, SMDS and DQDB

Describe Ethernet alternatives


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Chapter 64

Recall

10Base-T is the most commonly used Ethernetstandard, which provide transmission speed up to10 Mbps.

The 5-4-3 rule is designed for the number ofrepeaters and segments on shared access.

High speed Ethernet standards are:

Fast Ethernet (100Base Ethernet)

Gigabit Ethernet

10-Gigabit Ethernet


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Chapter 65

Token Ring - I

Token Ring is a network architecture developed byIBM

Also known as IEEE 802.5

Uses logical ring topology

Multiple MAUs can be connected to extend the ring


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Chapter 66

Token Ring - II

Data transfer is facilitated with the help of tokenpassing mechanism


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Chapter 67

Token Ring - III

Speed is either 4 or 16 Mbps

Performance is significantly faster than Ethernetnetworks

Uses physical star topology Hides logical ring inside a hub, known as

Multistation Access Unit (MAU)

Unshielded Twisted Pair (UTP) or Shielded TwistedPair (STP) cables are used connect nodes to thehub


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Chapter 68

Token Ring - IV

Advantages:

Data collision does not

occur

Every station isallowed to transmit

data

Time required to carry

the amount of data can

be calculated

Minimum cable

requirement

Disadvantages:

System collapses if

links between nodes

are malfunctioning

No alternative link to

transmit the data

Data transmission is

through single direction

Performance degrades

when junk data is

transmitted


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Chapter 69

Token Ring Vs Ethernet

Token Ring Ethernet

Token Ring network uses token passing mechanism. Ethernet network use CSMA/CD 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 specific time. Devices can transmit as soon as the medium is free.

Support heavy network traffic and maintains the network

performance.

The performance of the Ethernet network degrades as

network traffic increases.

Token Ring network is deterministic. Ethernet network is not deterministic as token ring.

Token ring network provides bandwidth efficiency up to

90%.

Ethernet network provides bandwidth efficiency up to 40%.

The network setup and maintenance of token ring is

expensive than Ethernet.

The cost of network equipment is lower for Ethernet.


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Chapter 610

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


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Chapter 611

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 itself. A virtual ring is formed over which the token is passed.

Defined by IEEE 802.5 standard. Defined by IEEE 802.4 standard

Does not provide better bandwidth as compared to token ring

network.

Uses broadband transmission and cabling which provides better

bandwidth.

In Token ring the maximum time that a token will take to reach the

end station can be calculated.

In Token Bus network the maximum time that a token will take to

reach the end station cannot be calculated.


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Chapter 612

Fiber LAN

Uses different types of fiber optic cables forinterconnection

Types of Fast Ethernet standards which use fiberoptic cables:

100BASE-FXUses two filaments of multi-modeoptical fiber cable. Maximum cable length is 400m

100BASE-SXUses two filaments of multi-modeoptical fiber cable. Maximum cable length is 300m

100BASE-BXUses single-mode fiber optic cable

FDDISupports 100 Mbps data rate over fiber opticcables


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Chapter 6 13

Fiber Distributed Data Interface

(FDDI)

Provides high performance and multiple stations

networking

Widely used in Metropolitan Area network

Based on token ring architecture


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Chapter 6 14

FDDINetwork Model

FDDI stations:

SingleAttached StationConnected through a single

connector called S-port

DualAttached StationConnected through A-portand B-port

FDDI concentrators:

SingleAttached ConcentratorConnected to the

FDDI network through a single connector DualAttached ConcentratorConnected to the FDDI

network through A-port and B-port


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Chapter 6 15

FDDIDevices

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


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Chapter 6 16

FDDIFailure Recovery

Wrapping ProcessModify 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 switchMaintain the network

connectivity by providing an optical connection thatbypasses the failed station


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Chapter 6 17

Copper Distributed Data Interface

(CDDI)

Version of FDDI

Uses twisted-pair copper cable instead of fiber optic

cable

Official name - Twisted-Pair Physical Medium-Dependent (TP-PMD)

Only two types of cables are supported by ANSI

standard for CDDI:

STP

UTP


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Chapter 6 18

Signaling and Connection Standards

Ensure that equipments to be used for creatingnetworks can work together

Signaling

Standards

FDDI FOIRL 10Base- F


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Chapter 6 19

Case Study

The accounts department of Money Maker Bank in

Mumbai is integrated using FDDI technology. One of

the computers have become non functional and asegment of cable has worn out. The computer needs

to be isolated from the network and the connectivity of

the network needs to be maintained.


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Chapter 6 20

Problem

Unable to identify failure recovery method


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Chapter 6 21

Suggested Solution

Use of optical bypass switches is needed to isolate

the computer from the network. The cable fault canbe rectified with wrapping.


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Chapter 6 22

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


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Chapter 6 23

ATMProtocol Reference Model

ATM protocol reference model describes thefunctions of different types of layers andorganizational units that act on data when it istransmitted using ATM technology.


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Chapter 6 24

ATMPerformance

ThroughputRate at which ATM cells depart from the

ATM switch

Connection Blocking ProbabilityDefines the probability

of Non-availability of enough resources for generating

physical connections between inlet and outlet

Cell Loss ProbabilityDefines a no. of data cell that can

be handled by a switch queue

Switching DelayTime required for cell to pass through

the ATM switch

Cell Delay VariationProbability that the switching delay

of the ATM switch exceeds the certain value


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Chapter 6 25

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 distributedclient-server networking system


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Chapter 6 26

AppleTalkNetwork Components

SocketsLocation in AppleTalk node which is

recognized by a unique address

NodesDevice which is a part of an AppleTalk

network e.g. computer, printer or router NetworksConsists of a cable with multiple nodes

connected to the cable

ZonesConstitutes a group of nodes and network

which are logically associated


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Chapter 6 27

AppleTalkNetwork 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 determinewhether it has been already utilized

Fields in AppleTalk network address:

Network number

Node number Socket number


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Chapter 6 28

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 forMacintosh computers

Implemented at the data link-layer

Uses network bus topology


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Chapter 6 29

ARCNET

Attached Resource Computer NETwork (ARCNET)

First LAN system introduced by Datapoint

Corporation

Uses a Token Passing bus structure similar toToken Ring

Logical structure is always a bus

255 nodes per network and supports speed up to 20

Mbps

supports segment lengths up to 600 meters


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Chapter 6 30

ARCNETDevices

Active HubSplits and amplifies the signal, isolates

the port electrically

Passive HubSplits signals

ARCNET Card - Different types of network interfacecard (NIC) can be used depending upon the type of

network topology

BNC TerminatorPrevent signal reflection in

network


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Chapter 6 31

ARCNET - Cables

Coaxial CableInexpensive and provide high

propagation factor

Unshielded Twisted Pair (UTP)Twisted pair

cables are easy to terminate Fiber OpticLower propagation factor than

coaxial cable


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Chapter 6 32

MAN

MAN connects different LANs Cover large distances to function across city

MAN Systems

Switched

Multimegabit

Data

Service (SMDS)

DistributedQueue

Dual Bus (DQDB)


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Chapter 6 33

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 wasprovided to the public

Packets transferred are of variable length and

contains the source and destination address

Allows the packets to flow from one LAN to another Standard speed is 45 Mbps


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Chapter 6 34

SMDS Network Components

Provide high-speed data transmission service

Network

Components

CustomerPremises

Equipment

(CPE)

Carrier

Equipment

SubscriberNetwork

Interface

(SNI)


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Chapter 6 35

SMDS Interface Protocol (SIP)

Connectionless service

Used for communication between CPE and SMDS

carrier equipment

Based on IEEE 802.6 Distributed Queue Dual Bus(DQDB) standards

Consists of three levels:

SIP Level 3

SIP Level 2

SIP Level 1


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Chapter 6 36

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 154Mbps

DQDB consists of two unidirectional buses


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Chapter 6 37

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 computerscan be connected into a LAN without running a wire

Three networking technologies are:

Wireless LANs

Phone line networks Power line networks


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Chapter 6 38

Wireless LANs

Wireless networks enable the user to move aroundthe house and use the computer.


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Chapter 6 39

Phone Line Networks

Phone line networks provide satisfactoryperformance at a much lower cost than wirelesssystems.


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Chapter 6 40

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 byinterference

Offer performance of 350 Kbps


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Chapter 6 41

Summary - I

The network arrangement and data communication isgiven by logical topology

Token ring and token bus are the two logical topologies

A token passing mechanism is used in both token ringand token bus

100Base-FX, 100 Base SX and 100BaseBX and FDDIare types of fiber LAN

Single-attached station (SAS) and Dual-attached station

(DAS) are the different types of FDDI stations SAS is connected to the FDDI network through a single

connector called S-port


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Chapter 6 42

Summary - II

Asynchronous Transfer Mode (ATM) network protocolconverts data into a stream of fixed size cell beforetransmission

Apple Computers has designed a protocol suite known

as AppleTalk The network components of AppleTalk are sockets,

nodes, network and zones

Attached Resource Computer NETwork (ARCNET), the

first LAN system and supports up to 255 nodes The different types of devices used in ARCnet are, active

hub, passive hub, ARCnet card and BNC terminator


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Summary - III

The most prominently used type of cabling for ARCnetare, coaxial cables, UTP and fiber optic

Point-to-point, distributed star, bus, daisy chain are thedifferent topologies which are suitable for ARCnet

MAN uses Switched Multimegabit Data Service (SMDS)and Distributed Queue Dual Bus (DQDB) systems

SMDS is a connectionless, high speed packet-switchedtechnology used for communication over public networks

DQDB is a Data-link layer communication protocol

IEEE 802.6 standard uses DQDB network form The Ethernet alternatives are, Wireless LANs, Phone

line networks and Power line networks

chapter 6 other network architecture

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