EDUSAT SESSION FOR COMPUTER NETWORKSI CS64

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EDUSAT SESSION FOR COMPUTER NETWORKS-I
(CS64) Date 01.03.2006 Session I Topic
Introduction and Uses of N/W Faculty Anita
Kanavalli MSRIT
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Course Overview

• Introduction to Computer Networks
• LANs
• Network Layer
• Transport Layer
• ATM Networks

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Text Reference Books

• Text Books
• - Computer Networks, By Andrew S Tanenbaum
  Fourth Edition PHI
• - Communication Networks Fundamental Concepts
  and Key Architectures, By Alberto Leon Garcia
  and Indra Widjaja TMH second edition

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Text Reference Books

• Reference Books
• - Data communications and Networking, By Behrouz
  A Forouzan TMH Third edition
• - Data and Computer Communication, By William
  Stallings Fifth Edition PHI
• - Computer Networking A Top Down approach
  featuring the internet By J F Kurose Keith W
  RossSecond edition PHI

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Computer Network?

A computer network is a collection of computers
and other devices (nodes) that use a common
network protocol to share resources with each
other over a network medium. interconnected
collection of autonomous computers connected by a
single technology Tanenbaum
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Why Computer Network?

• To share information or receive a service via a
  network, group members must be able to
  communicate with each other.

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Communication Model

• Source
• Generates data to be transmitted
• Transmitter
• Converts data into transmittable signals
• Transmission System
• Carries data
• Receiver
• Converts received signal into data
• Destination
• Takes incoming data

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Communication Model

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Communication Model

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Classification of Computer Networks

• Wired, Wireless and Fiber Optic Networks
• LANs, MANs and WANs
• Circuit Switched, Packet Switched and Virtual
• Circuit Switched Networks
• Access, Edge and Core Networks

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Classification of Computer Networks

• Architecture
• Common LAN architectures Ethernet IEEE 802.3,
  Token Ring, and FDDI.
• Access Possibilities
• shared-media networks
• switching networks
• Transmission Technology
• Broadcast links
• Point-to-point links

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Wired Network

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Wireless Network

shared wireless access network connects end
system to router via base station aka access
point wireless LANs 802.11b (WiFi) 11 Mbps
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Fiber Optic Network

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LANs

• company/univ local area network (LAN) connects
  end system to edge router
• Ethernet
• shared or dedicated link connects end system
  and router
• 10 Mbs, 100Mbps, Gigabit Ethernet
• deployment institutions, home LANs happening now

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MAN

A cable TV is an example of MAN
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WANs

• Spans a large geographic area, e.g., a country
  or a continent
• A WAN consists of several transmission lines and
  routers
• Internet is an example of a WAN

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Circuit Switched Network

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Packet Switched Network

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Virtual Circuit Switched Network

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Access Edge/Core

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Internetworking ?

• internetwork interconnection of networks
  also called an internet
• Subnetwork a constituent of an internet
• Intermediate system a device used to connect
  two networks
• allowing hosts of the networks to correspond
  with each other
• Bridge
• Routers
• Internet is an example of an internetwork.

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What is Internet ?

network of networks collection of networks
interconnected by routers a communication
medium used by millions Email, chat, Web
surfing, streaming media
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What is Internet ?

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What is Internet ?

• millions of connected computing devices hosts,
  end-systems
• PCs workstations, servers
• PDAs phones, toasters
• running network apps
• communication links
• fiber, copper, radio, satellite
• Links have different bandwidth
• routers forward packets
• Packet a piece of messg.

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Uses of Computer Networks

• Business applications
• Resource sharing
• Example-client server model
• E-mail
• E-commerce

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Application 1


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Application 1

• end systems (hosts)
• run application programs
• e.g. Web, email
• at edge of network
• client/server model
• client host requests, receives service from
  always-on server
• e.g. Web browser/server email client/server
• Client/server model is applicable in an intranet.

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Uses of Computer Networks

• Home applications
• Access to remote information
• Person to person communication
• Interactive entertainment
• E-commerce

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Uses of Computer Networks

• Mobile users
• PDA
• WAP 1.0
• Social Issues