Internet Technologies[1]

8/14/2019 Internet Technologies[1]

1/37

Introduction

Internet is an interconnection between the computers cited at the remotelocations in the world wide web (www) . The Internet is a huge network ofcomputers, which links many different types of computers all over the world.Internet is a network of networks or collection of LANs (Local AreaNetworks) which share a common set of protocols for communicationsbetween two computers between the LANs.

The Internet has its root in the ARPANET system of the Advancedresearch Project Agency of the US Department of Defence . ARPANET wasthe first WAN (Wide Area Network) and had only four sites in 1969.

In the 1980s the National Science Foundation of USA officially created theInternet.

Intranet is the Interconnection between the computers cited at the remotelocations pertaining to only one organization.


2/37

Services Provided by the Internet E-mail : E-mail provides a mechanism for groups of people who have

common interests to establish and maintain contact. FTP : FTP is an abbreviation for File Transfer Protocol. FTP is used to send

a copy of a file from a one computer to another. The files can be sent acrossusing FTP include spreadsheets , digitized pictures , sound files , programs, word processed files etc.

TELNET : This service allows you to log-on to a remote machine , on whichyou have your account.

Usenet Newsgroups : There are many ways to meet people and shareinformation using Internet. One such way is Usenet newsgroups. Theseare special groups set up by people who want to share common interestsranging from current topics to cultural heritage. There are currentlythousand of newsgroups.


3/37

Network can be classified into twocategories:

Point to Point channel network : The two computers thatare not connected by a cable can communicate only viaother intermediate components. The information isstored in its entirety and later forwarded when the line is

free. This is also called as packet switching. Broadcast channel network : A single channel will be shared by all

the machines on the network. There is an address field within themessage that specifies the destination. This network is calledmultidrop network.


4/37

Three most commonly used networksare

LAN: Uses broadcast channel for communication. Spansan area of not more than a few kilometers. Atotal datarate of several mbps. Owned by a single organization.

WAN : Uses point to point links. Spans the entirecountry. Has a data rate below 1 Mbps. Owned bymultiple organizations.

MAN : This lies between LAN and WAN. Uses LANtechnology. Spans the entire city.


5/37

TOPOLOGIES

Star : A central hub is connected to various computers. The hub is in complete controlof all computers and is responsible for routing traffic. It is easy to identify the faultpoints by isolating the lines.

Hierarchical : Also known as vertical network or tree network. The computer at thehighest level of hierarchy is in control of the network. Any number of subordinatecomputers can be added to the network.

Bus : A single station broadcasts to multiple stations. Only one communicationchannel exists for all the devices on the network. If the main communication channelfails , the entire network crashes. It is difficult to isolate faults to one particularcomponent that is connected to the bus. This is used in LAN.

Ring : It is widely used for network configuration. Data flow is in one direction only.One computer receives the signal and relays it to the next computer on the ring. It is amajor drawback because if a channel between two nodes fails , the network is lost.

We can build bypass switches to avoid such failures.


6/37

Global Reach / Penetration ofInteractive Services: Total internet users in Europe and in the World: [Internet World Stats, January 2006]

Europe: 290,121,957

World: 1,018,057,389

Total internet users by country and share of world users: 202,888,307 (21.6% share) [Nielsen// NetRatings, June, 2005] China: 103,000,000 (11%) [CNNIC, June, 2005] Japan: 78,050,000 (8.3%) [C+I+A, March, 2005] Germany: 47,127,725 (5.0%) [Nielsen// NetRatings , June, 2005] India: 39,200,000 (4.2) [ C.I.Almanac , March, 2005] UK: 35,807,929 (3.8%) [Nielsen// NetRatings, June, 2005]

There will be 1.07 billion internet users globally by 2005, 1.21 billion by 2006 and 1.35 billion by 2007.[ eTForecasts , Sept 2004]


7/37

India Internet andTelecommunications Reports

July 7, 2004 - Women lead rural India's internet rush. The internet isbeginning to have a revolutionary effect on the 700 million peoplewho live in villages in India - and the charge is being led by women.A project set up by one of India's leading technology institutes has

put women in charge of forging the way across the digital divide asthe proprietors of a fast-growing number of internet cafes or kiosksaround the sub-continent. In total 80% of these new kiosks are runby women, many of whom have had very little or no acquaintancewith technology before. ( BBC News).


8/37

India - Internet and E-Services MarketReport Despite the considerable popular interest in Internet in India, the ISP

market has been in disarray. According to the telecom regulator, there werearound 180 operational ISPs in the country, after a period of marketrationalization . Despite the large number of providers, 10% of the ISPshave 90% of the subscribers. The state-owned BSNL and MTNL havegrown rapidly to hold first and second place in terms of subscribers. Thegrowing popularity of cyber cafes has been playing a big role in fuellingInternet development in India. This report looks at the ISPs and otheraspects of Indias Internet market. There is also some information onInternet content and e-services.


9/37

India - Broadband and Data ServicesReport

February 16, 2006 - Broadband usage in India isgrowing 20% per month, according to the InternetService Providers Association of India (ISPAI).Thanks to the progress in the past two years andespecially, the Broadband Policy announced ayear ago, the term broadband has entered masslexicon and most Internet users are aware offaster speeds. ( ISPAI Article).


10/37

February 17, 2006 - An overview ofInternet usage in India.

The state-owned Videsh Sanchar Nigam Limited (VSNL)launched Internet Services in India in August 1995. For thefirst four years , VSNL was the sole provider of InternetServices in the Country. In November 1998, the Government

ended VSNLs monopoly and allowed provisioning of InternetServices by Private Operators. The Terms and Conditions ofthe ISPs License were unusually liberal with no License Feeand allowed unlimited number of players. ISPs could set theirown tariffs and even their own International Gateways.


11/37

InternetAddresses

The Internet is a interconnection between the computers cited at theremote site that are able to talk to each other in spite of the fact that theymay be separated by large distances, may be very different computers builtby different manufacturers, and may be running many different kinds ofoperating systems. This is similar to people in (say) India,Israel, Brazil,Japan, spain,the United States, and pakistan, each normally speaking adifferent language, being able to converse almost instantaneously witheach other on very broad ranges of topics!

The computers of the Internet exchange packets of information usingaddresses . These addresses are called Internet Protocol (IP) addresses.


12/37

TCP/IP Protocols

The communications between the computers arepossible because of a set ofprotocols, which is aset of rules about exactly how information will betransferred between the computers of the Internet.

The two most important protocols that allownetworks to cooperate with one another andexchange information are called TCP(Transmission Control Protocol) and IP (InternetProtocol). Collectively, these two protocols are

known as TCP/IP.


13/37

Packets of Information

The information is transferred in terms of electronic packets.Packets must have an address. TCP/IP communication

depends on addresses being included in each packet. theseaddresses are commonly termed "IP addresses". As thesepackets of information move through the network, electronicdevices called routers use these IP addresses to decidewhether to keep a packet in a local network or to forward it to

a different network. This is a complex task, because there aremany networks that either comprise the Internet, or that areattached to it through some gateway.


14/37

Addresses

Each computer has a number that tells you many things about it. Onthe internet each machine is assigned a host number which is a 32-bit binary number: four numbers separated by dots.

Addresses for Internet information packets have four fields thatcontain numbers and are separated by periods. For example,100.35.04.15 is an IP address. However, people generally canremember names better than numbers, so it is convenient toassociate a name with such an IP address. In this case, the

corresponding name is www.arsdcollege.net.


15/37

The Naming System

Let us consider as a typical example the internet address

www.arsdcollege.net , which is actually the name of the IPaddress 50.26.24.07. How did the people who run theInternet come up with that name, and how did we know

that www.arsdcollege.net is really a nickname for50.26.24.07?

The symbolic name of a site is determined by a namingstandard known as the Domain Name System or DNS.

DNS is a textual addressing method.

Each field in a symbolic address corresponds to a singledomain. The first field is a host name, which identifies asingle computer. The last field is a top level domain. Inbetween are things like department names, organizationnames, and so on in order of increasing generality.

URL D t il
http://www.arsdcollege.net/http://www.arsdcollege.net/


16/37

URL Details

The URL(Uniform Resource Locator) provides a

reasonably intelligent form to uniquely identify or

address information on the internet.

URL addresses have 2 parts: (1) a portion

specifying the method of file access, and (2) a

portion specifying the Internet location of the file to

be accessed.

The example of the address

http://www.arsdcollege.net/index.html


17/37

Search Engines

A search engine is a program that can search the Web on aspecific topic for you. By typing in a word or phrase (known as akeyword), the search engine will produce pages of links on thattopic. Supposedly, the more relevant links are at the top of the list,but that is not always true. To understand more specifically how

search engines, operate visit How Search Engines Work.Example: the Searchalot Search Engine

An example of a search engine is the popular Searchalot SearchEngine. The homepage of this web site includes a small window,which you can type a word or set of words on a topic you areinterested in.

Suppose you wanted to locate information about Cricket on theWeb. You could go to the searchalot site and enter your query inthe entry field:


18/37


19/37

You then press on " Search" (other search

engines will have slightly different forms). Thesearch engine will respond by providing you with a

list of all the documents in its database that

contain the word cricket". Your browser will

display a page with your keyword(s) and a list ofdocuments in which the engine found the word(s).

For a searchalot search on cricket", the results

will look like:


20/37


21/37

Sharpening the Search

If the keyword you specify for the search is a rather commonterm, you may be presented with an enormous number ofWeb documents that contain that term. In this case many ofthe hits may contain the term but in only one or two instances.Rather than wasting a lot of your time looking through the longlist and visiting links that may turn out to have little or nothingto do with the topic you are really interested in, you can let thesearch engine do the sifting by repeating your search withadditional and more specific keywords.


22/37

General tips to help your search: Be as specific as possible. For example, maybe you are really only

interested in cricket information on the delhi clubs, then you shoulduse the term delhi clubs" instead of the general term of cricket."

If you're truly interested in the Delhi clubs" wrap the term in quotes.This means you want both words together. Otherwise you will pull

travel web sites about the city of Delhi .On most search enginesadding a plus sign (+) next to any term means to be sure andinclude the term in the results. If you want very specific informationabout the Delhi clubs 2007 season , put a plus sign (+) next toboth terms. For example +Delhi clubs " and +2007 means that youwant only links that have both information about the clubsand their

activities during the year 2007.


23/37

Other Search Engines

There are many search engines besides the Search alot service availableon the Web. Here are the links for some other popular ones:

AltaVista (www.altavista.com)

Northern Light (www.northernlight.com)Excite (www.excite.com)

Google

Yahoo. There may be minor differences in the details of their use, most of these

engines behave in a similar way, accepting a list of keywords from you andreturning a list of documents that contain those keywords. Keep in mind that

if you don't find the results you're looking for in one search engine, tryanother because each search engine analyzes the Web a different way.


24/37

Search engines can access a broad range of material on the Web,depending on search strings used. Thus, unsupervised use ofsearch engines by students can lead to access of inappropriatematerial.

If you intend to use search engines directly in your classes . There

are some search engines try to prevent this.Searchenginewatch.com has a list of the search engines on theirweb site that attempt to screen inappropriate material.

Also, you may find it useful to warn your students that it is possibleto go back and find out from the computer which files andaddresses have been accessed by the Web browser on that

computer .


25/37

Directories

A directory is built by someone looking at a web site todetermine if it's worthy of being added to their databaseand if so, under what category it should fall. Regular

search engines are not so discerning. As you mightsuspect, directories don't cover as much of the Web as asearch engine, and there is the potential element ofhuman bias in categorization.

Many directories have search tools to help you find

specific items within each category. For Example Looksmart and yahoo.


26/37

COPY RIGHT RULES

1. Something appears on the Internet does not mean that it is legalfor you to copy it.

2. The law generally holds that it is your responsibility to determinethe legality of copying something, irrespective of whether thesource from which you copy it has broken the law or not.

3. A related point to keep in mind is that when, as in the case of theTutorial, someone gives you permission to use their material, thispermission does not extend to material that may be accessed bya link from the original material. The question of how materialaccessed in an external link may be used clearly must be put toits owner.


27/37

4. You should Notice carefully the distinction: you

may usually insert a link to someone elses Web

material in your pages without restriction; the

issue of ownership becomes important only when

you attempt to download material from other Web

sites and incorporate it directly into your Web

material.


28/37

Cyber Laws in India In May 2000, both the houses of the Indian Parliament passed the

Information Technology Bill. The Bill received the assent of thePresident in August 2000 and came to be known as the InformationTechnology Act, 2000. Cyber laws are contained in the IT Act,2000.

This Act aims to provide the legal infrastructure for e-commerce inIndia.The Act states that unless otherwise agreed, an acceptance ofcontract may be expressed by electronic means of communicationand the same shall have legal validity and enforceability (DIT).


29/37

Advantages of Cyber Rules

The IT Act 2000 provides ways to deal with cyber crimes. We needsuch laws so that people can perform purchase transactions overthe Net through credit cards without fear of misuse. In view of thegrowth in transactions and communications carried out through

electronic records, the Act seeks to empower governmentdepartments to accept filing, creating and retention of officialdocuments in the digital format. The Act has also proposed a legalframework for the authentication and origin of electronic records /communications through digital signature (DIT).


30/37

From the perspective of e-commerce in India, the IT Act 2000 and its provisions contain many positiveaspects. Firstly, the implications of these provisions for the e-businesses would be that email would now bea valid and legal form of communication in our country that can be duly produced and approved in a courtof law.

Companies shall now be able to carry out electronic commerce using the legal infrastructure . Digital

signatures have been given legal validity and sanction in the Act.

The Act throws open the doors for the entry of corporate companies in the business of being CertifyingAuthorities for issuing Digital Signatures Certificates.

The Act now allows Government to issue notification on the web thus heralding e-governance.

The Act enables the companies to file any form, application or any other document with any office,authority, body or agency owned or controlled by the appropriate Government in electronic form by means

of such electronic form as may be prescribed by the appropriate Government. The IT Act also addresses the important issues of security, which are so critical to the success of electronic

transactions. The Act has given a legal definition to the concept of secure digital signatures that would berequired to have been passed through a system of a security procedure, as stipulated by the Governmentat a later date.

Under the IT Act, 2000, it shall now be possible for corporates to have a statutory remedy in case if anyonebreaks into their computer systems or network and causes damages or copies data. The remedy providedby the Act is in the form of monetary damages, not exceeding Rs. 1 crore.

( Department Of Information technology.)


31/37

Ways to speedup download time: When there is an addition of graphic ,audio and video files to a web site and if any

user wants to access this website then there will be delay in downloading. Cut out unnecessary HTML such as comments , font changes and table

elements that are needed. Use cascading Style Sheet to control appearance rather than changing fonts and

appearance on every page.

Always use correct width and height attributes in image tags. Resize and resample the graphics. Lower the quality settings of JPEG files. Use GIFs instead of JPGs when possible. Lower the resolution of a high resolution graphic. Display a low-resolution version of a graphic while downloading. Create thumbnail. Display alt text. Split content into more pages.

Avoid unnecessary use of multimedia content like java applets, movies,images,animation and other elements


32/37

Uses of the Internet:

On-line communication Software Sharing Exchange of views on topic of common interest Posting of information of general interest Product promotion Feed back about products Customer support service On-line journals and magazines On- line shopping World wide video conferencing Education and training Entertainment Banking and financial transactions


33/37

What user expect to find on website:The user should be involved in clicking and entering there choices rather than being static

watchers. The level of success is based on the level of user satisfaction: 1. Users do not enjoy getting lost, having system lockup or being tricked. 2. Users like to be able to click any where at any time and get what they want. 3. Users enjoy being in control and having easy navigation and multiple choices. 4. User demand fast loading pages and go elsewhere if they do not get them.

5.User cannot see image maps or graphics due to technology limitations. 6. Users often dislikes clumsy frames and bothersome drop down menus. 7. User likes hyper text links but hate entry tunnels like Click here to enter. 8. Users often do not have 256 colors so many graphics look bad in just 16. 9. Users say they return to site that treat them well as a web customer. 10. Users prefer to click through multiple short pages than wait for long one. 11. Users love pictures prefer being told how big they are so they can deside whether

to load them or not. 12. Users have little idea about how internet magic works but know instantly which

sites they prefer and which they will bookmark for for later viewing. 13. Users know the Internet is not Television ,but still expect the web to grab their

attention in engaging and interactive way. 14. Users enjoy being part of an online community so chat features bolted on to a site

can triple session lengths, double Kb per user and page impression downloads per

session , bolster visit frequency by over 50 % , and work a sites servers a great dealharder. Most web users are simply not Cookie Monsters and are turned off if they are


34/37

Some Important Internet Terms Archie : A program used to search files at FTP sites .There are currently 30 Archie servers

in the world. Web site : Collection of web pages. Home page: The main page of a web site. Host : A computer system that is the source of network services. HTTP: The client server protocol upon which the www is based.

IP : Allows a packet to travel through multiple networks on the way to its destination. IP Address: A unique number assigned to every computer directly connected to internet. Browser : System Program that allows you to surf the web. Site : A place on the Internet. Every web page has a location where it resides, which is

called its site. Spam : Spamming is sending the message to a large number of users, usually to advertise

something means the Internet version of junk mails. Surfing: The process of looking around the Internet.

URL : Address of web site. WWW : Is a universal mass of web pages connected together through links.


35/37

WIRELESS TECHNOLOGIES

Over recent years, the market for wireless

communications has enjoyed tremendous

growth. Wireless technology now reachesvertually every location on the face of the

earth.


36/37

Types of wireless

Wireless Local Area Networks 802.11b (Wireless Eathernet) 802.11a , HiperLAN ii , and homeRF Fixed Broadband Wireless Multiservice Wide Area Networks. Mobile Wireless Wireless Personal Area Networks Based on Bluetooth technologies :Bluetooth in its most basic form is cable

replacement. Where cable now connect many devices, Awireless bluetoothconnection will provide low cost wireless communications and networking

between PCs, mobile phones and other devices. Bluetooth is an RF(radio frequency) technology for short- range wireless networking.


37/37

WAP

WAP is wireless application protocol which

allows web-like content to be sent to mobile

devices.

Date post:	30-May-2018
Category:	Documents
Upload:	tanayaroy
View:	220 times
Download:	0 times

Internet Technologies[1]

Documents