Internet and Www Infrastructure

8/14/2019 Internet and Www Infrastructure

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Internet and wwwInternet and www


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Learning Objective The Internet Technology Concepts

Internet II: The Future Infrastructure

The World Wide Web

The Internet and The Web features

Security Environments and Threats

Technology Solutions

Payment Systems

Digital Payment System in B2C Arena

Digital Payment System in B2B Arena


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InternetInternet

An interconnected network ofAn interconnected network of

thousands of networks and millions ofthousands of networks and millions of

computers linking business, educationalcomputers linking business, educational

institutions, government agencies andinstitutions, government agencies andindividuals together.individuals together.

The largest collection of networks in theThe largest collection of networks in the

world, interconnected to allow them toworld, interconnected to allow them tofunction as a single virtual networkfunction as a single virtual network


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Early history of InternetEarly history of Internet

In the 1950s the U.S. Department of DefenseIn the 1950s the U.S. Department of Defense became concerned that a nuclear attack couldbecame concerned that a nuclear attack could

disable its computing (and thus planning anddisable its computing (and thus planning and

coordinating) capabilities.coordinating) capabilities.

By 1969 the Advanced Research Projects AgencyBy 1969 the Advanced Research Projects Agency Network (ARPANet) had been constructed.Network (ARPANet) had been constructed.

The first computers to be connected were ones atThe first computers to be connected were ones at the University of California at Los Angeles, SRIthe University of California at Los Angeles, SRI

International, the University of California atInternational, the University of California at

Santa Barbara, and the University of Utah.Santa Barbara, and the University of Utah.


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TerminologyTerminology

AA hypertext serverhypertext serveris a computer that storesis a computer that storesfilesfiles written in hypertext markup language (HTML)written in hypertext markup language (HTML)

and lets other computers connect to it and readand lets other computers connect to it and read

those files. It is now called athose files. It is now called a Web serverWeb server.. AA hyperlinkhyperlinkis a special tag that contains ais a special tag that contains a

pointerpointer to another location in the same or in a differentto another location in the same or in a different

HTML document.HTML document.

HTML is based on Standard Generalized MarkupHTML is based on Standard Generalized Markup Language (SGML), which organizations haveLanguage (SGML), which organizations have

used for many years to manage large documentused for many years to manage large document

filing systems.filing systems.


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Local Area Network (LAN)Local Area Network (LAN)

A link-up of workstations andA link-up of workstations and

peripheral equipment in an office,peripheral equipment in an office,

building, or locality so users maybuilding, or locality so users may

communicate and share equipmentcommunicate and share equipmentand information.and information.

LAN lets you share the resources ofLAN lets you share the resources of

other computersother computers LAN can be further characterized byLAN can be further characterized by

topologytopology


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TopologyTopology

Topology describe the manner inTopology describe the manner in

which various computer nodes arewhich various computer nodes are

interconnected to each otherinterconnected to each other

In this context LAN have threeIn this context LAN have three

prevalent topologies:prevalent topologies:

BusBus

RingRing

StarStar


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Bus TopologyBus Topology

Consists of nodes connected to a singleConsists of nodes connected to a singlebus made up of a long cable.bus made up of a long cable.

A thick coaxial cable may serve as the busA thick coaxial cable may serve as the busand all computer nodes are connected toand all computer nodes are connected tothis running coaxial cablethis running coaxial cable

The computer nodes directly receive andThe computer nodes directly receive andinject data from the bus in full duplexinject data from the bus in full duplexmode of operation. Data traverses in bothmode of operation. Data traverses in both

directiondirection Endpoints of the bus have terminators andEndpoints of the bus have terminators and

absorbs all signals reaching them.absorbs all signals reaching them.


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Ring TopologyRing Topology

Nodes are organized to form a ringNodes are organized to form a ring

structurestructure

The first node is connected to secondThe first node is connected to second

using linkusing link Second is connected to third and so onSecond is connected to third and so on

The last node is connected to first usingThe last node is connected to first using

point to point link.point to point link. Signals travel internally around theSignals travel internally around the

network from one node to othernetwork from one node to other


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Star TopologyStar Topology

Each computer node is connected toEach computer node is connected toa central devicea central device

Nodes are located at one end of theNodes are located at one end of the

segment and other end is terminatedsegment and other end is terminatedin a central device, usually a hub orin a central device, usually a hub ora switcha switch

Reliable topologyReliable topology If one node is down, others onIf one node is down, others on

network are not affected.network are not affected.


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PacketsPackets

PacketPacket: Parcel into which digital messages are: Parcel into which digital messages aresliced for transmission over the internet.sliced for transmission over the internet.A sequence of data, with associated controlA sequence of data, with associated control

information, that is switched and transmittedinformation, that is switched and transmitted

as a wholeas a whole Packet SwitchingPacket Switching: A method of slicing digital: A method of slicing digital

messages into packets, sending the packetsmessages into packets, sending the packets

along different communication paths as theyalong different communication paths as they

become available and then reassembling thebecome available and then reassembling thepackets once they arrive at destination.packets once they arrive at destination.


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Packet TransmissionPacket Transmission In packaged switched networks, firstIn packaged switched networks, first

messages are broken down intomessages are broken down intopackets. Appended to each digitalpackets. Appended to each digitalcodes that indicate:codes that indicate: Source addressSource address

DestinationDestination

Sequencing InformationSequencing Information

Error Control InformationError Control Information

In a packet network, packets travelIn a packet network, packets travelfrom computer to computer untilfrom computer to computer untilthey reach their destinationthey reach their destination


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I want to chat with you00101101000010010010000

01101101 10101000 11000011

0011001 10101100 11000011

Packet Switching

Original Message

Text Message digitized

into bits

Digital Bits broken into

packets

Header information added

to each packet indicating

destination, and other

control information such as

how many bits are in thetotal message and how

many packets

Digital messages are divide into fixed length

packets of bits, Header information indicatesboth the origin and destination address of

the packet, the size of the message, and the

number of packets the receiving node

should expect.


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RoutersRouters

Special purpose computers thatSpecial purpose computers that

interconnect the computer networks thatinterconnect the computer networks that

make up the internetmake up the internet

Route packets to their ultimate destinationRoute packets to their ultimate destinationas they travel the internet.as they travel the internet.

Routing AlgorithmRouting Algorithm: Computer program that: Computer program that

ensures that packets take the bestensures that packets take the best

available path toward their destination.available path toward their destination.


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ProtocolProtocol

A set of rules for formatting, ordering,A set of rules for formatting, ordering,

compressing, and error checkingcompressing, and error checking

messages. It may also specify themessages. It may also specify the

speed of transmission and means byspeed of transmission and means bywhich device on network will indicatewhich device on network will indicate

they have stooped sending and / orthey have stooped sending and / or

receiving messages.receiving messages.


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Internet ProtocolInternet Protocol

Protocol that provides the InternetProtocol that provides the Internetaddress schemeaddress scheme

Internet address is expressed as 32Internet address is expressed as 32

bit numbers that appears as a seriesbit numbers that appears as a seriesof four separate numbers marked offof four separate numbers marked offby periods such as 210.61.186.227by periods such as 210.61.186.227

Each of 4 numbers can range from 0Each of 4 numbers can range from 0 255. This dotted quad scheme 255. This dotted quad schemecontains up to 4 billion addresses.contains up to 4 billion addresses.


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IP AddressIP Address

All the host connected to InternetAll the host connected to Internet

have an officially address.have an officially address.

It is 4 bytes long and written inIt is 4 bytes long and written in

dotted decimal notation.dotted decimal notation.

For example IP AddressFor example IP Address

10000001.1000000.00000100.00000110000001.1000000.00000100.00000101 can be written as 129.128.4.501 can be written as 129.128.4.5


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Transmission Control ProtocolTransmission Control Protocol

Protocol that establishes theProtocol that establishes the

connection among sending andconnection among sending and

receiving web computers, handlesreceiving web computers, handles

the assembly of packets at the pointthe assembly of packets at the pointof transmission and their reassemblyof transmission and their reassembly

at the receiving end.at the receiving end.


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TCP / IP LayersTCP / IP Layers

Network Interface LayerNetwork Interface Layer: Responsible for: Responsible forplacing packets on and receiving themplacing packets on and receiving them

from the network medium, which could befrom the network medium, which could be

a local area network (Ethernet) or Tokena local area network (Ethernet) or TokenRing or other network topology.Ring or other network topology.

Internet LayerInternet Layer: This layer is responsible for: This layer is responsible foraddressing, packaging, and routingaddressing, packaging, and routing

messages on the Internet.messages on the Internet.


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TCP / IP LayersTCP / IP Layers

Transport LayerTransport Layer: Responsible for: Responsible forproviding communication with theproviding communication with theapplication by acknowledging andapplication by acknowledging andsequencing the packets to and fro fromsequencing the packets to and fro fromthe application.the application.

Application LayerApplication Layer: Provides a wide variety: Provides a wide varietyof applications with the ability to accessof applications with the ability to access

services of the lower layersservices of the lower layers

Some of the best applications areSome of the best applications areFTP,SMTP and HTTPFTP,SMTP and HTTP


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Domain Name: Most people can not remember 32 bit address. IPaddress can be represented by a natural language convention called domainnames

Domain Name System: for expressing numeric address innatural language

Uniform Resource Locator: Address used by a web browserto identify the location of content on the web

DomainDomainDomainDomain


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Domain Name SystemDomain Name System

DNS SERVERS: Are databases that keeptrack of IP addresses and domainnames.

ROOT SERVERS: are central directoriesthat list all domain names currently inuse. DNS server consult root servers tolook up unfamiliar domain names whenrouting traffic


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Client Server ComputingClient Server Computing

A model of computing in which veryA model of computing in which very

powerful personal computer arepowerful personal computer are

connected together in a network withconnected together in a network with

one or more servers.one or more servers. Internet is a giant example of clientInternet is a giant example of client

server computingserver computing


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Client, ServerClient, Server

CLIENTCLIENT: A powerful personal computer that is: A powerful personal computer that ispart of a network. That is capable of displayingpart of a network. That is capable of displaying

rich graphics storing large files and processingrich graphics storing large files and processing

sound and graphic files.sound and graphic files.

SERVERSERVER:: Networked computer dedicated toNetworked computer dedicated tocommon functions that the client machines oncommon functions that the client machines on

the network need, such as storing files, softwarethe network need, such as storing files, software

applications, utility programs such as webapplications, utility programs such as web

connections and printersconnections and printers


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Hyper Text Transfer ProtocolHyper Text Transfer Protocol

The set of rules for exchanging files (text,The set of rules for exchanging files (text,graphic images, sound, video, and othergraphic images, sound, video, and othermultimedia files) on the World Wide Web.multimedia files) on the World Wide Web.

Runs in the application layer of the TCP/IPRuns in the application layer of the TCP/IPmodel. An HTTP session begins when amodel. An HTTP session begins when aclients browser requests a web page fromclients browser requests a web page fromremote internet serverremote internet server

When the server responds by sending theWhen the server responds by sending the

page requested, the HTTP session for thatpage requested, the HTTP session for thatobject endsobject ends


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SMTP, IMAP, POPSMTP, IMAP, POP

SMTPSMTP: Internet protocol used to send mail: Internet protocol used to send mailto server (Simple Mail Transfer Protocol)to server (Simple Mail Transfer Protocol)

POPPOP: Post Office Protocol, a protocol used: Post Office Protocol, a protocol used

by the client to receive the mail from anby the client to receive the mail from aninternet server.internet server.

IMAPIMAP: a more current e-mail protocol that: a more current e-mail protocol thatallows users to search, organize, and filterallows users to search, organize, and filter

their mail prior to downloading it from thetheir mail prior to downloading it from theserver (Internet Message Access Protocol)server (Internet Message Access Protocol)


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Simple Network ManagementSimple Network Management

ProtocolProtocol

SNMPSNMP is the protocol governingis the protocol governing

network management and thenetwork management and the

monitoring of network devices andmonitoring of network devices and

their functions.their functions.


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FTP Internet service that allow you to transfer file

from one computer to another computerusing client/server technology

You run a client program on your computerwhich connects to a server program on a

remote computer When you copy a file from remote server we

say that you are downloading and when youcopy a file from your computer to remote oneyou are uploading the file

In FTP terminology your computer is LOCALHOST, the other computer is REMOTE HOST


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FTPFTP


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TelnetTelnet Telnet is a internet service that allow you to logTelnet is a internet service that allow you to log

in to a remote internet computerin to a remote internet computer To utilize this service, you need a Telnet clientTo utilize this service, you need a Telnet client

on your machine. Client uses internet toon your machine. Client uses internet to

connect to the remote computerconnect to the remote computer

Once the connection is made, the client acts asOnce the connection is made, the client acts asintermediary between remote and yourintermediary between remote and your

computercomputer

Every thing you type on your machine is passedEvery thing you type on your machine is passed

on to the remote computeron to the remote computer Everything the other computer displays is sentEverything the other computer displays is sent

to your computerto your computer


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TelnetTelnet


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FingerFinger

Finding People on the Internet. YouFinding People on the Internet. You

can find out who is logged on to acan find out who is logged on to a

remote network by using Telnet toremote network by using Telnet to

connect to a server and then typingconnect to a server and then typingfingerfinger at the prompt.at the prompt.

Finger can tell you who is logged inFinger can tell you who is logged in

and how long they have beenand how long they have beenattached and their user nameattached and their user name


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FingerFinger


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PingPing

Testing address. You can ping a hostTesting address. You can ping a host

computer to check the connectioncomputer to check the connection

between your client and server. Thebetween your client and server. The

Ping will also tell you the time itPing will also tell you the time ittakes for the server to respondtakes for the server to respond

giving some idea of the internetgiving some idea of the internet

speed at that time (Packet Internetspeed at that time (Packet InternetGroper)Groper)


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Ping CommandPing Command


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TracertTracert

One of the several route tracingOne of the several route tracing

utilities that allow you to follow theutilities that allow you to follow the

path of a message you send frompath of a message you send from

your client to a remote computer onyour client to a remote computer onthe internetthe internet


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MiddlewareMiddleware

It is the glue that ties the applicationIt is the glue that ties the application

to the communications networks andto the communications networks and

includes such services as security,includes such services as security,

authentication. Addresses andauthentication. Addresses andstorage repositories.storage repositories.

Users rarely become aware ofUsers rarely become aware of

middleware that operate in themiddleware that operate in thebackground.background.


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NetworksNetworks

Network Access PointNetwork Access Point: One of the hubs: One of the hubswhere the backbone intersects withwhere the backbone intersects withregional and local networks andregional and local networks and

where the backbone owners connectwhere the backbone owners connectwith one another.with one another. Campus NetworkCampus Network: LAN operating within: LAN operating within

a single organization that leasesa single organization that leases

access to the web directly fromaccess to the web directly fromregional or national carriersregional or national carriers


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Internet Service ProviderInternet Service Provider

Firm that provides the lowest level ofFirm that provides the lowest level of

service in the multi-tiered internetservice in the multi-tiered internet

architecture by leasing internetarchitecture by leasing internet

access to home owners, smallaccess to home owners, smallbusiness, and some large institutionsbusiness, and some large institutions


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BandwidthBandwidth

BroadbandBroadband: Refers to any: Refers to anycommunication technology thatcommunication technology thatpermits client to play streamingpermits client to play streaming

audio and video files at acceptableaudio and video files at acceptablespeeds generally anything abovespeeds generally anything above100 kbps.100 kbps.

DSLDSL:A telephone technology for:A telephone technology for

delivering high-speed access throughdelivering high-speed access throughordinary telephone lines found inordinary telephone lines found inhome or business.home or business.


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Cable ModemCable Modem

Cable ModemCable Modem: A cable television: A cable television

technology that piggybacks digitaltechnology that piggybacks digital

access to the internet on top of theaccess to the internet on top of the

analogue video cable providinganalogue video cable providingtelevision signals to a home.television signals to a home.


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Intranet and ExtranetIntranet and Extranet

IntranetIntranet: A TCP/IP network located: A TCP/IP network locatedwithin a single organization forwithin a single organization for

purpose of communication andpurpose of communication and

information processing.information processing.

ExtranetExtranet: Formed when firm permits: Formed when firm permitsoutsiders to access their internaloutsiders to access their internal

TCP/IP networks.TCP/IP networks.

L i Obj ti


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The World Wide Web




Payment Systems




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Limitations of Internet ILimitations of Internet I BandwidthBandwidth: Slow service and a very limited: Slow service and a very limited

capacity to handle video and voice traffic.capacity to handle video and voice traffic.

Quality of ServiceQuality of Service: Packets take circuitous: Packets take circuitousroot to reach destination. This results inroot to reach destination. This results in

latency. With streaming video andlatency. With streaming video andsynchronous communication, latency issynchronous communication, latency is

noticeable and user perceives jerkiness innoticeable and user perceives jerkiness in

movies and delay in voice communication.movies and delay in voice communication.

LatencyLatency: uneven flow of information: uneven flow of informationpackets throughout the networkpackets throughout the network


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Limitations of Internet ILimitations of Internet I

Network ArchitectureNetwork Architecture: A thousand requests for single: A thousand requests for singlemusic track from a central server will result in amusic track from a central server will result in a

thousand efforts by the server to download thethousand efforts by the server to download the

music to each requesting client. This slows downmusic to each requesting client. This slows down

network performance.network performance.

Language DevelopmentLanguage Development: HTML the language of the: HTML the language of theweb pages is fine for text and simple graphics butweb pages is fine for text and simple graphics but

poor at defining rich graphic and communicatingpoor at defining rich graphic and communicating

rich documents such as databases, business rich documents such as databases, business

documents, or graphics.documents, or graphics.


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Internet2 ProjectInternet2 Project

It is a consortium of more than 180It is a consortium of more than 180universities, government agenciesuniversities, government agenciesand private business that areand private business that are

collaborating to find ways to makecollaborating to find ways to makethe Internet more efficient.the Internet more efficient. To create a joint test bed where newTo create a joint test bed where new

technologies can be tested with outtechnologies can be tested with out

impacting the existing Internet.impacting the existing Internet.


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Features on Internet2Features on Internet2

Advance Network InfrastructureAdvance Network Infrastructure

High performance backbone networksHigh performance backbone networks

with bandwidth ranging from 2.5 Gbpswith bandwidth ranging from 2.5 Gbps

to 9.6 Gbps that interconnect a gigapop.to 9.6 Gbps that interconnect a gigapop. Gigapop is regional gigabit point ofGigapop is regional gigabit point of

presence, or point of access to thepresence, or point of access to the

Internet2 network that supports dataInternet2 network that supports data

transfers at the rate of 1 gbps or higher.transfers at the rate of 1 gbps or higher.


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Larger Technology EnvironmentLarger Technology Environment

Fibre-optic CableFibre-optic Cable: Consists up to hundreds of: Consists up to hundreds ofstrands of glass or plastic that use light tostrands of glass or plastic that use light to

transmit data. It is frequently existingtransmit data. It is frequently existing

coaxial and twisted pair of cables.coaxial and twisted pair of cables.

PhotonicsPhotonics: The study of communicating with: The study of communicating withlight waveslight waves

Dense Wavelength Division MultiplexingDense Wavelength Division Multiplexing: An optical: An optical

technology to increase bandwidth overtechnology to increase bandwidth over

existing fibre-optic backboneexisting fibre-optic backbone


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Technology EnvironmentTechnology Environment

Big BandBig Band: Can accommodate upwards: Can accommodate upwardsof 1 Gbps applications.of 1 Gbps applications.

GSMGSM: Mobile communications that: Mobile communications that

uses narrowband Time Divisionuses narrowband Time DivisionMultiple Access.Multiple Access.

CDMACDMA: Uses full spectrum of radio: Uses full spectrum of radio

frequencies and digitally encryptsfrequencies and digitally encryptseach calleach call


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GPRSGPRS: Next generation technology carries: Next generation technology carriesdata in packets, just like the Internet, butdata in packets, just like the Internet, butover radio frequencies that makes wirelessover radio frequencies that makes wirelesscommunications possible.communications possible.

WAPWAP: A relatively new protocol that can: A relatively new protocol that cansupport virtually any wireless network andsupport virtually any wireless network andis supported by every operating system.is supported by every operating system.

Wireless Mark up LanguageWireless Mark up Language: Programming: Programminglanguage for devices using WAP.language for devices using WAP.


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iModeiMode:: Wireless standard that isWireless standard that ispropriety service of the Japanesepropriety service of the Japanesecompany NIM DoCoMocompany NIM DoCoMo

3G3G: New generation of cellular phone: New generation of cellular phonestandards that can connect users tostandards that can connect users tothe web.the web.

BluetoothBluetooth: New technology standard: New technology standard

for short range wirelessfor short range wirelesscommunication under 100 metrescommunication under 100 metres


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Wi-FiWi-Fi (wireless Fidelity): Also refer to(wireless Fidelity): Also refer to802.11B wireless standard for Ethernet802.11B wireless standard for Ethernetnetworks with greater speed and range thannetworks with greater speed and range thanBluetooth enabling:Bluetooth enabling:

Handheld device can become multi-functionalHandheld device can become multi-functionalunits, serving as a credit cards, identificationunits, serving as a credit cards, identificationbadge and key all in one.badge and key all in one.

Documents can be printed by any printer withinDocuments can be printed by any printer withinrange or faxed via a local machine.range or faxed via a local machine.

Highway toll can be paid via PDAHighway toll can be paid via PDA


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Internet AppliancesInternet Appliances Internet II infrastructure will make it possible to connectInternet II infrastructure will make it possible to connect

nearly all the electronic devices to internets and intranets.nearly all the electronic devices to internets and intranets. User will be able to activate or deactivate virtually anyUser will be able to activate or deactivate virtually any

device that can be connected to Internet, such as TV, AC,device that can be connected to Internet, such as TV, AC,

Security System etc.Security System etc.

Where the receiving device is relies totally on the InternetWhere the receiving device is relies totally on the Internet

server to handle all information processing; the deviceserver to handle all information processing; the deviceitself has no processing ability, is calleditself has no processing ability, is called Thin Client.Thin Client.

Thin clientThin client also refers to PC with out hard Disk.also refers to PC with out hard Disk.


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IP MulticastingIP Multicasting

A set of technologies that enablesA set of technologies that enables

efficient delivery of data to manyefficient delivery of data to many

locations on a network.locations on a network.

Multicasting initially just sends oneMulticasting initially just sends one

message and does not copy it to themessage and does not copy it to the

individual recipients until it reachesindividual recipients until it reaches

the common closest point on thethe common closest point on thenetwork.network.


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Guaranteed Service LevelsGuaranteed Service Levels With Internet II, it will be possible toWith Internet II, it will be possible to

purchase the right to move datapurchase the right to move datathrough the network at a guaranteedthrough the network at a guaranteedspeed in return for higher fees.speed in return for higher fees.

Low Error LevelsLow Error Levels: Improve quality of data: Improve quality of data

transmission reducing error rates.transmission reducing error rates. Declining CostsDeclining Costs: Availability of broad band: Availability of broad band

will significantly reduce the cost. Morewill significantly reduce the cost. More

users means lower cost as product andusers means lower cost as product andtechnology catch on in the masstechnology catch on in the massmarket.market.


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New Network CapabilitiesNew Network Capabilities

Developing the IPV6 addressing protocolDeveloping the IPV6 addressing protocol Developing and implementing new qualityDeveloping and implementing new quality

of service technologies.of service technologies. Developing more effective routingDeveloping more effective routing

practices.practices. Coordinating the interconnection ofCoordinating the interconnection of

different component of the Internet2different component of the Internet2infrastructure Backbone, LAN, Campusinfrastructure Backbone, LAN, Campus

Creating an infrastructure to efficientlyCreating an infrastructure to efficientlyhandle one-to-many communications overhandle one-to-many communications overthe Internet.the Internet.

Learning Objective


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The World Wide Web




Payment Systems




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HypertextHypertext It is a way of formatting pages with embeddedIt is a way of formatting pages with embedded

links that connects documents to one another, andlinks that connects documents to one another, andthat also links pages to other objects such asthat also links pages to other objects such as

sound, video, or animation files.sound, video, or animation files.

When you type a web address in you browser suchWhen you type a web address in you browser such

asas http://www.imt.eduhttp://www.imt.edu, your browser sends an, your browser sends anHTTP request to the imt.edu server requesting theHTTP request to the imt.edu server requesting the

home page of imt.eduhome page of imt.edu

HTTP is the first set of letter at the start of everyHTTP is the first set of letter at the start of every

web address followed by the domain name.web address followed by the domain name.
http://www.imt.edu/http://www.imt.edu/http://www.imt.edu/


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Uniform Resource LocatorUniform Resource Locator

The directory path and documentThe directory path and documentname are two more pieces ofname are two more pieces ofinformation with the web addressinformation with the web addressthat help the browser track down thethat help the browser track down therequested page.requested page.

Together the address is called a URL.Together the address is called a URL.When typed into a browser, a URLWhen typed into a browser, a URL

tells exactly where to look fortells exactly where to look forinformation. For example:information. For example:http://www.imt.edu/dlp/pgdbm.htmhttp://www.imt.edu/dlp/pgdbm.htm
http://www.imt.edu/dlp/pgdbm.htmhttp://www.imt.edu/dlp/pgdbm.htmhttp://www.imt.edu/dlp/pgdbm.htm


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Mark Up LanguagesMark Up Languages

SGMLSGML: Standard Generalized Markup: Standard Generalized MarkupLanguage. The purpose of SGML wasLanguage. The purpose of SGML wasto help very large organizationsto help very large organizationsformat and categorize largeformat and categorize largecollection of documents.collection of documents.

It can run independent of anyIt can run independent of anysoftware program, but it is extremelysoftware program, but it is extremely

completed and difficult to learn.completed and difficult to learn. An early version of GeneralizedAn early version of Generalized

Markup languageMarkup language


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Extensible Markup LanguageExtensible Markup Language

XML is a new Markup languageXML is a new Markup languagespecification developed by W3C. It is aspecification developed by W3C. It is a

Markup language like HTML but with aMarkup language like HTML but with a

different purpose. XML is designed todifferent purpose. XML is designed to

describe data and information.describe data and information. XML can be used to define databaseXML can be used to define database

records and this will enablerecords and this will enable

organizations to put most of theirorganizations to put most of theirinformation processing functions intoinformation processing functions into

an Internet processing environmentan Internet processing environment

W b S S f


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Web Server SoftwareWeb Server Software That enables a computer to deliver webThat enables a computer to deliver web

pages written in HTML to client machines onpages written in HTML to client machines ona network that request this service bya network that request this service by

sending an HTTP request.sending an HTTP request.

Two leading brand of the software areTwo leading brand of the software are

Apache, which is the free web serverApache, which is the free web server

shareware that accounts for 60% of theshareware that accounts for 60% of the

market, and windows NT Server softwaremarket, and windows NT Server software

that accounts for 20% of the market.that accounts for 20% of the market.


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Other ServersOther Servers

Database ServerDatabase Server: That access specific: That access specific

information with a database.information with a database.

Ad ServersAd Servers: Designed to deliver: Designed to deliver

targeted banners ads.targeted banners ads. Mail ServerMail Server: That provides mail: That provides mail

Messages.Messages.

Video ServerVideo Server: That serves video clips.: That serves video clips.


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Web ClientsWeb Clients

Any computer device attach to theAny computer device attach to theInternet that is capable of makingInternet that is capable of makingHTTP requests and displaying HTMLHTTP requests and displaying HTMLpages, most commonly a Window orpages, most commonly a Window orMacintosh PC with various flavour ofMacintosh PC with various flavour ofUNIX machines.UNIX machines.

However the fastest growing webHowever the fastest growing web

clients are PDAs and cellular phonesclients are PDAs and cellular phonesfitted with wireless web accessfitted with wireless web accesssoftware.software.

Learning Objective


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The World Wide Web




Payment Systems




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Electronic MailElectronic Mail

The most used application of theThe most used application of theInternetInternet

Uses a series of protocols to enableUses a series of protocols to enable

messages containing text, images,messages containing text, images,sound and video clips to besound and video clips to betransferred from one internet user totransferred from one internet user toanotheranother

AttachmentAttachment: A file inserted with in the: A file inserted with in thee-mail message.e-mail message.

SpamSpam: Unsolicited e-mail.: Unsolicited e-mail.


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IntelligentIntelligentSearch Bot Altivista.com


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IntelligentIntelligent

AgentsAgents Or SoftwareOr Software

Robots (bots)Robots (bots)are softwareare softwareprograms thatprograms thatgather and / orgather and / orfilter informationfilter informationon specific topicon specific topicand then provideand then providea list of resultsa list of results

for the user.for the user.

Webcrawler

Shopping Bot MySimonDealTime

Update Bot UrlyWarning

News Bot WebClippingSportSpider

Chatter Bot eGainNativeMinds


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Instant messagingInstant messaging

Displays word type on computerDisplays word type on computer

almost instantaneously. Recipientsalmost instantaneously. Recipients

then can respond immediately tothen can respond immediately to

sender the same way, making thesender the same way, making thecommunication more like a livecommunication more like a live

conversation than is possible throughconversation than is possible through

e-mail.e-mail.

Ch tCh t


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ChatChat Enables user to communicate via computer inEnables user to communicate via computer in

real time, that is simultaneously, unlike Instantreal time, that is simultaneously, unlike InstantMessaging chat can occur among severalMessaging chat can occur among several

users.users.

CookiesCookies: are a tool used by web sites to store: are a tool used by web sites to store

information about a user. When visitor entersinformation about a user. When visitor entersa web site, site sends a small text file to thea web site, site sends a small text file to the

users computer so that information from theusers computer so that information from the

site can be loaded more quickly on future visitssite can be loaded more quickly on future visits


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Streaming MediaStreaming Media

Enables music, video and other largeEnables music, video and other large

files to be sent to users in chunks sofiles to be sent to users in chunks so

that when received and played, thethat when received and played, the

files comes through uninterrupted.files comes through uninterrupted. Streamed files must be viewed live,Streamed files must be viewed live,

They can not be stored on client hardThey can not be stored on client hard

drive.drive. RealAudio and RealVideo are the mostRealAudio and RealVideo are the most

widely used streaming tools.widely used streaming tools.


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IP TelephonyIP Telephony

A general term for the technologyA general term for the technology

that use VOIP and the Internet packetthat use VOIP and the Internet packet

switched network to transmit voiceswitched network to transmit voice

and other forms of audioand other forms of audiocommunication over the Internet.communication over the Internet.

VOIP Protocol VOIP Protocol: Protocol that allows: Protocol that allows

transmission voice and other forms oftransmission voice and other forms ofaudio communication over theaudio communication over the

Internet.Internet.


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Digital LibraryDigital Library

As bandwidth capabilities of theAs bandwidth capabilities of theInternet increase, digital librariesInternet increase, digital librariesand software applications willand software applications willemerge as companies and individualsemerge as companies and individualselect to rent software rather thanelect to rent software rather thanbuy it.buy it.

Accessing a web server will enable aAccessing a web server will enable a

user to download the desireduser to download the desiredsoftware by paying a subscription feesoftware by paying a subscription feeinstead of purchase priceinstead of purchase price


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Learning Objective


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The World Wide Web




Payment Systems



Date post:	30-May-2018
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