16479_Internet vs Intranet vs Extranet

8/2/2019 16479_Internet vs Intranet vs Extranet

1/46

ITEC 1010 Information and Organizations

The Internet, Intranets, and

Extranets


2/46


The Internet

The internet

A network of networks

The internet transmits data from one computer(called a host) to another

Internet networks

Linked networks that work much the sameway -- they pass data around in packets, eachof which carries the addresses of its sender andreceiver Schematic


3/46



4/46


Internet Discussion (1)

A global network connecting millions of computers. As of 1999, the

Internet has more than 200 million users worldwide, and that number

is growing rapidly. More than 100 countries are linked into

exchanges of data, news and opinions.

Unlike online services, which are centrally controlled, the Internet is

decentralized by design. Each Internet computer, called a host, is

independent. Its operators can choose which Internet services to

use and which local services to make available to the global Internet

community. Remarkably, this anarchy by design works exceedingly


5/46


Internet Discussion (2)

well.

There are a variety of ways to access the Internet. Most onlineservices, such as America Online, offer access to some Internet

services. It is also possible to gain access through a commercial

Internet Service Provider (ISP).

Note: York Universitys CCS (Computer and Communications

Services) is an ISP.


6/46


How the Internet Works

Transport control protocol (TCP)

A protocol that operates at the transport layer and isused in combination with IP by most Internet

applications Backbone

An Internet high-speed, long distance communicationslinks (like a bus; wire that connects nodes)

Uniform resource locator (URL) An assigned address on the Internet for each computer

E.g., http://www.yorku.ca/


7/46


Domain Affiliations

Domain Affiliationsarts cultural and entertainment activities

com business organizations

edu educational sites

firm businesses and firms

gov government sitesinfo information service providers

mil military sites

nom individuals

net networking organizations

org organizationsrec recreational activities

store businesses offering goods for purchase

web entities related to World Wide Web activities

net networking organizations


8/46


Access to the Internet

LAN servers Local servers can provide access to the Internet through

normal connections (e.g., Ethernet)

Serial line internet protocol (SLIP) and

Point-to-point protocol (PPP) Communications protocol software that transmits packets over

telephone lines, allowing dial-up access to the Internet

Connection via an on-line service Examples are America Online and Microsoft Network. These

services usually require sign-up procedures


9/46


Three Ways to Access the

Internet

Schematic


10/46



11/46


Internet Service Providers

Internet service provider (ISP)

Any company that provides individuals or

companies with access to the Internet

Thousands of providers including large

communications companies

Need an account with the ISP and softwarethat links with TCP/IP


12/46


ISP Examples

Internet Service Provider Web Address

AT&T WorldNet Service www.att.com

Digex, Inc. www.digex.net

GTE Internetworking www.gte.net

IBM Internet Connection www.ibm.net

MCI Internet www.mci2000.com

NetCom On-Line CommunicationServices

www.netcom.com

PSINet, Inc. www.psinet.com

Sprint Internet Services www.sprint.net

Uunet Technologies, Inc. www.us.uu.net


13/46


Internet Services

E-mail

Telnet

FTP

Usenet and newsgroups

Chat rooms

Internet phone Internet videoconferencing

Content streaming


14/46


Selected Usenet Groups

alt.fan.addams.family alt.life.itself

alt.pets alt.fan.bevis-n-butthead

alt.autos.camaro alt.fan.leonardo-dicaprio

alt.cloning alt.history

alt.fan.u2 alt.music.blues

alt.sports.baseball.cinci-red alt.music.zz-top

alt.politics.socialism alt.sports.college.sec

alt.sports.soccer.european.uk


15/46


Internet Services

Internet telephony

Also called voice-over-IP (VOIP)

Technology that enables network managers to routephone calls and fax transmissions over the same

network they use for data


16/46



17/46


VOIP Discussion

Internet telephony is a category of hardware and software that

enables people to use the Internet as the transmission medium for

telephone calls. For users who have free, or fixed-price, Internet

access, Internet telephony software essentially provides free

telephone calls anywhere in the world. To date, however, Internettelephony does not offer the same quality of telephone service as

direct telephone connections.

There are many Internet telephony applications available. Some,

like CoolTalk and NetMeeting, come bundled with popular Webbrowsers. Others are stand-alone products. Internet telephony

products are sometimes called IP telephony, Voice over the Internet

(VOI) or Voice over IP (VOIP) products.


18/46


Content Streaming

Content streaming A method for transferring multimedia files over the

Internet so that the data stream of voice and picturesplays continuously, without a break, or very few of

them

It also enables users to browse large files in real

time


19/46


The World Wide Web

World Wide Web A collection of tens of thousands of independently-

owned computers that work together as one in anInternet service


20/46


WWW Terminology

Home page The cover page for a Web site that has graphics,

titles, coloured text, etc.

Hypermedia Tools that connect the data on Web pages, allowing

users to access topics in whatever order they wish

Hypertext markup language (HTML) The standard page description language for Web

pages


21/46


Some Interesting Web Sites

Library of Congress http://lcweb.loc.gov

PointCast http://www.pointcast.com

In-Box Direct http://www.netscape.com

Online Career Center http://occ.com

New York Times http://www.nytimes.com

Project Gutenberg http://www.gutenberg.org

Sportsline USA http://www.sportsline.com

White House http://www.whitehouse.govMIT Lab for Computer Science http://www.lcs.mit.edu

The Wall Street Journal http://www.wsj.com


22/46


WWW Terminology

Web browser Software that creates a unique hypermedia-based

menu on your computer screen and provides agraphical interface to the Web

Web page A screen of information sent to a requesting user

and presented through a browser

Applet A small program embedded in Web pages


23/46


HTML

The language of WWW pages

Need we say more!!!


24/46


Search Engines

Search engines

A search tool for the Web (like card catalogs in

libraries) E.g., Altavista http://www.altavista.digital.com

Excite http://www.excite.com

Galaxy http://www.einet.net

Hotbot http://www.hotbot.com

Infoseek http://www.infoseek.com

Lycos http://www.lycos.com

Webcrawler http://www.webcrawler.com

Yahoo! http://www.yahoo.com


25/46


Java

Java

An object-oriented programming language

Developed by Sun Microsystems

Based on C++

Allows small programs -- applets -- to be

embedded within an HTML document


26/46


Applets

Applets are small java programs that are

downloaded from the server to the local

machine


27/46


Push Technology

Push technology Technology that enables users to automatically

receive information over the Internet rather thansearching for it using a browser

Also called Webcasting

E.g.,

PointCast InterMind


28/46


Webcasting Discussion

Using the Internet, and the World Wide Web in particular, to

broadcast information. Unlike typical surfing, which relies on a pull

method of transferring Web pages, webcasting uses pushtechnologies.


29/46


Push Discussion (1)

In client/server applications, to send data to a client without

the client requesting it. The World Wide Web is based on a pull

technology where the client browser must request a Web page

before it is sent. Broadcast media, on the other hand, are push

technologies because they send information out regardless of

whether anyone is tuned in.

Increasingly, companies are using the Internet to deliver information

push-style. One of the most successful examples of this is

PointCast, which delivers customized news to users' desktops.


30/46


Push Discussion (2)

Probably the oldest and most widely used push technology is e-mail.

This is a push technology because you receive mail whether you ask

for it or not -- that is, the sender pushes the message to the

receiver.


31/46


Business Use of the Web

Uses:

Applications, E-mail, Product Display, Catalogs,Order placement

Products people are likely to buy on the WebSoftware 77%

Books 67%

CDs 64%

Computer hardware 63%

Airline tickets 61%

Magazine subscriptions 53%

Concert/theater tickets 48%

Flowers 45%


32/46


Intranets and Extranets

Intranet An internal corporate network built using Internet

and World Wide Web standards and products thatallows employees of an organization to gain access

to corporate information

Extranet

A network based on Web technologies that linksselected resources of the intranet of a company with

its customers, suppliers, or other business partners


33/46


Intranet Discussion

A network based on TCP/IP protocols (an internet) belonging to an

organization, usually a corporation, accessible only by the

organization's members, employees, or others with authorization. An

intranet's Web sites look and act just like any other Web sites, but

the firewall surrounding an intranet fends off unauthorized access.

Like the Internet itself, intranets are used to share information.

Secure intranets are now the fastest-growing segment of the

Internet because they are much less expensive to build and manage

than private networks based on proprietary protocols.


34/46


Extranet Discussion

A new buzzword that refers to an intranet that is partially

accessible to authorized outsiders. Whereas an intranet resides

behind a firewall and is accessible only to people who are members

of the same company or organization, an extranet provides various

levels of accessibility to outsiders. You can access an extranet only

if you have a valid username and password, and your identity

determines which parts of the extranet you can view.

Extranets are becoming a very popular means for business partners

to exchange information.


35/46

ITEC 1010Information and Organizations

Virtual Private Network (VPN)

Virtual Private Network (VPN) A secure connection between two points across the

Internet Tunneling

The process by which VPNs transfer information byencapsulating traffic in IP packets and sending the

packets over the Internet

Schematic


36/46



37/46


VPN Discussion

Short for virtual private network, a network that is constructed by

using public wires to connect nodes. For example, there are a

number of systems that enable you to create networks using the

Internet as the medium for transporting data. These systems use

encryption and other security mechanisms to ensure that only

authorized users can access the network and that the data cannot

be intercepted.


38/46


Tunneling Discussion

A technology that enables one network to send its data via another

network's connections. Tunneling works by encapsulating a network

protocol within packets carried by the second network. For example,

Microsoft's PPTP technology enables organizations to use the

Internet to transmit data across a virtual private network (VPN). It

does this by embedding its own network protocol within the TCP/IP

packets carried by the Internet. (Note: PPTP = point-to-point tunneling

protocol)

Tunneling is also called encapsulation.


39/46


Internet Issues

Management issues

No centralized governing body for the Internet

Service bottlenecks

Phenomenal growth has left a service void

Providers underestimating computing power

needed Reconciling router addresses needed to

transverse the network


40/46


Privacy & Security

Cryptography The process of converting a message into a secret code and

changing the encoded message back to regular text

Encryption The original conversion of a message into a secret code

Digital Signature An encryption technique used for online financial transactions


41/46


Have a

nice day

Have a

nice day

Encryption

software

running on

sending

computer

Decryption

software

running on

Receiving

computer

E%$&:}{|


42/46


Firewalls

Firewalls A method of preventing unauthorized access

between a companys computers and the Internet(looks at the header of a packet)

Assured pipeline

An Internet security method that looks at the entire

request for data and then determines whether therequest is valid


43/46


Firewall Discussion (1)

A system designed to prevent unauthorized access to or from a

private network. Firewalls can be implemented in both hardware and

software, or a combination of both. Firewalls are frequently used to

prevent unauthorized Internet users from accessing private

networks connected to the Internet, especially intranets. All

messages entering or leaving the intranet pass through the firewall,

which examines each message and blocks those that do not meetthe specified security criteria.


44/46



There are several types of firewall techniques:

Packet filter: Looks at each packet entering or leaving the network andaccepts or rejects it based on user-defined rules. Packet filtering is fairlyeffective and transparent to users, but it is difficult to configure. In addition, it

is susceptible to IP spoofing. Application gateway: Applies security mechanisms to specific applications,

such as FTP and Telnet servers. This is very effective, but can impose aperformance degradation.

Circuit-level gateway: Applies security mechanisms when a TCP or UDP

connection is established. Once the connection has been made, packets canflow between the hosts without further checking.

Proxy server: Intercepts all messages entering and leaving the network. Theproxy server effectively hides the true network addresses.


45/46



In practice, many firewalls use two or more of these techniques in

concert.

A firewall is considered a first line of defense in protecting private

information. For greater security, data can be encrypted.


46/46

ITEC 1010

?

16479_Internet vs Intranet vs Extranet

Documents

Intranet, Extranet, Firewall - ERNET

internet intranet and extranet

Extranets in SharePoint - Extranet User Manager...SharePoint Licensing–2010 vs 2013 2013 Intranet Extranet Internet Sites Internal Users SharePoint Server + CAL SharePoint Server

internet, intranet, extranet y VOIP

Difference Between Intranet And Extranet

IT-Internet,Intranet and Extranet

32 Internet Intranet Extranet

Internet, Intranet e Extranet

INTRANET EXTRANET

Intranet Si Extranet - En

Intranet and extranet best practices

Information Security Internet, Intranet, Extranet

Internet,E-Mails, Intranet ,Extranet

Internet intranet extranet aaa

Internet/Intranet/Extranet and Virtual Private Network (VPN)eestaff.kku.ac.th/~nararat/EN253206/Ch14VPN.pdf · • An intranet is sometimes contrasted to an extranet. While an intranet

Internet, intranet and extranet

Internet Extranet Intranet

Internet, Intranet & Extranet

Intranet & Extranet Social Innovation€¦ · Intranet & Extranet Social Innovation . † Panelists • Andy Steggles, President, Higher Logic • Lorri Wyndham, Director of Operations,

INTRANET VS EXTRANET