comp ntwrkz lec 1

8/8/2019 Comp Ntwrkz Lec 1

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Course Overview and Introduction to

Computer Networks

Computer Communicationsand Networks

(lecture 1)

Aadil Zia Khan


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Agenda Course Overview & Teaching

Style.

Introduction to and Applications ofComputer Networks.


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Teaching Style

Interactive.

Application of concepts.

Quizzes in almost every class.

Assignments to test concepts.

In class practice questions.


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Description & Objective

Introduce you to computer networks

and communications concepts.

See how they give strategicadvantage in businesses.

Enable you to study new

technologies in information and

communication technologies on your

own.


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T

ext Book Primary

Data Communications and

Computer Networks A BusinessUsers Approach, 5th Ed., Cengage

Learning, 2009.

Reference

Handouts and Case Studies may beprovided.


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Course Group http://groups.google.com/group/co

mputernetworksbnu


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GradeD

istribution Quizzes & Assignments 30%

Mid Term Exam 30%

Final Exam 40%

May vary if need be


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Agenda Introduction to computer and

communication networks concepts.

Definitions.

Real life uses and applications of

networks.


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The Language of

Computer Networks Computer network an

interconnection of computers and

computing equipment using eitherelectrical wires, radio waves or

optical fibers over small or large

geographic areas.


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The Language of

Computer Networks Local area network networks that

are small in geographic size

spanning a room, floor, building, orcampus.

For example

Network within a university.

Network within a software house.

Computer Gaming in LAN Parties.


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The Language of

Computer Networks Wide area network (WAN)???


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The Language of

Computer Networks Wide area network a large

network that encompasses parts of

states, multiple states, countries,and the world.

The internet.


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The Language of

Computer Networks Metropolitan area network

networks that span a typical city.

For example Different offices of the same

company (mobilink service centers)

might be connected together using a

high speed link. Different universities of Lahore can

be connected by a dedicated link.


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The Language of

Computer Networks Personal area network a network

of a few meters, between wireless

devices such as PDAs, laptops, andsimilar devices.

For example synchronizing your

phones address book with your

computers address book.


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The Language of

Computer Networks Voice network a network that

transmits only voice signals.

Almost extinct.

For example

Walkie Talkies.

Rescue 1122 communication

network.


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The Language of

Computer Networks Data network a network that

transmits voice and computer data.

Convergence- previously disjoint,voice and data traffic is serviced by

the same network.

For example

Cell phone transmits voice.

Cell phone can be used to browse

the internet.

Cell phone can be used take

pictures and forward them to friends.


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The Language of

Computer Networks Data communications the actual

transfer/transmission of voice or

data over some network.


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The Language of

Computer Networks Telecommunications the study of

telephones and the systems that

transmit telephone signals. Gradually becoming simply data

communications since telecom

service providers provide data

communication services (like SMS,MMS and email) as well.


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The Language of

Computer Networks Network measurementthe

measurement of bandwidth and

latency of the links in a network. Latency - total time taken for

data/voice to reach the destination.

Bandwidth - amount of data that can

be carried from one point to anotherin a given time period.

Useful for fault diagnoses and

optimization.


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Anatomy of Networks

Workstations

Computers, tablets, PDA.

End users of the network.


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Anatomy of Networks

Servers

Provide service to the end users.

Webpages.

Instant messaging.

Email.

Share files.

Movies and mp3s.


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Anatomy of Networks

Network hubs

Connect work stations and servers.

Any data packet coming from oneport is sent to all other ports.

Port is where a work station

connects to the network.

Port is an interface.

Receiving computer decides if the

packet is for it.


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Anatomy of Networks

Network hubs

Problem

Since every packet is sent out toevery computer on the network,

there is a lot of wasted transmission.

Wasted transmission causes

inefficiency due to collisions. Typically used on small networks.


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Anatomy of Networks

Network bridges

A bridge goes one step up on a hub

in that it looks at the destination ofthe packet before sending.

It maintains list of destinations

available at a port. If the destination

address is not on a port it will nottransmit the data on that port.

Typically used to separate parts of a

network that do not communicate

regularly.


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Anatomy of Networks

Routers

Connect LAN to WAN and WAN to

WAN. Responsible for finding the shortest

paths (sort of) between source and

destination.


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Anatomy of Networks

Switches

Generic term for machines which

forward data packets intelligently. Router is layer 3 switch.

Bridge is layer 2 switch.

More on this and on layering in later

lectures.


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Anatomy of Networks

Protocol

Special set of rules that end points

in a telecommunication connectionuse to establish connection and

communicate.


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Networks all around us

Why should you be studying

computer and communications

networks. Networks are all around us.

They make life easier.

They give strategic advantage in

businesses.


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Enterprise Resource Planning

Systems

An integrated information systemthat serves all departments within an

enterprise. HR, Finance, Sales etc.

Impossible without data

communication between thesedepartments.

Impossible without data

communication between workstation

and ERP System.


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Distributed Teams

Virtual workspace

Taking example of a softwareindustry, one team member may in

USA while the other would be in

Pakistan.


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Business at the speed of thought

Book written by Bill Gates on how

business and technology areintegrated, and how digital

infrastructures and information

networks can help getting an edge

on the competition.


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Due to technology, the speed of

business is accelerating at an ever-increasing rate, and to survive, it

must develop an infrastructure--a

"digital nervous system"--that allows

for the unfettered movement ofinformation inside a company.


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Gates writes that "The most

meaningful way to differentiate yourcompany from your competition ... is

to do an outstanding job with

information. How you gather,

manage, and use information willdetermine whether you win or lose.


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Teradata-Coca Cola Japan

Teradata is a company which

provides tools for data warehousingand data mining.

managing massive amount of data

and gathering important information

and patterns from this data. Coca Cola Japan used Teradata as

backend for its vending machines.

On stock depletion, the information

was quickly communicated.


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Viral Marketing

These days many companies use

sites like youtube to upload videoswhich advertise their products. This

saves money since Television Ads

are expensive.


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Sensor Networks

These are networks in which

sensors take reading of theenvironment and share the

information.

Can be used to monitor crops.

Can be used in safety criticalenvironments.

Other situations???


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RFID Networks

Radio Frequency Identification

Object of interest, such as cargo, isassigned an RFID.

RFID Tags transmit information

used to monitor the location.

Can also be used to monitor quality.For example vegetable cargo can be

damaged if the warehouse

temperature increases.

Motorway toll plazas use RFID tags.


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Vehicular Networks

A network is maintained between

the moving vehicles. Can be used for predicting and

avoiding traffic jams, collisions etc.


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Emergency Services

Have been cases where patient

stuck in a remote area carried outsurgery on themselves, while being

guided online by a surgeon miles

apart.


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Distance Learning

People having access to the internet

can study at a foreign universityfrom the comfort of their homes.

Population in remote and rural areas

can get quick access to education.

Virtual University Pakistan.


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Ubiquitous Computing

The time is near when computers

would be ubiquitous. You will manage your microwave

oven, bath tub etc. from your office

desktop.

You will switch on and off yourelectrical appliances using SMS etc.


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Military

Future battles will be fought from a

single room. Drones are a preview of what is to

come.

In the near future, drones,

unmanned surveillance groundvehicles tanks, and just maybe

human fighters, would be

communicating in real time to fight

battles.


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E-Services

Buy tickets, reserve airline seats.

24-hour banking. Pay bills.

Do shopping (Ebay,Amazon).


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Staying Connected

Social Networking (Orkut, LinkedIn)

Email Much faster than the traditional snail

mail approach.

Cheaper telephones

There was a time a call to USA costhundreds of rupees per minute.

Voice over IP (VoIP) has made it

free/almost free.

Skype, GoogleTalk etc.


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File Sharing

Share important data with ease.

Future is paperless offices.


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Leisure

Internet Browsing.

Watch videos online. Listen to online radios.

IPTV.


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References

Course book slides.

Wiki.

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