INTRODUCTION TO INFORMATION SYSTEMS LECTURE 10: NETWORK, COMMUNICATION AND ITS APPLICATION أ/ غدير عاشور 1

Network Concepts 2  Network  An interconnected chain, group or system  Number of possible connections on a network is N * (N-1)  Where N = number of nodes (points of connections on the network)  Example, if there are 10 computers on a network, there are 10 * 9 = 90 possible connections

Metcalfe’s Law 3  The usefulness of a network equals the square of the number of users  On a small network, a change in technology affects technology only  On a large network like the Internet, (where a critical mass of users is reached), a change in technology affects social, political and economic systems

Telecommunications 4  Telecommunications  Exchange of information in any form (voice, data, text, images, audio, video) over networks

Trends in Telecommunications 5  Industry Trends  Technology trends  Business application trends

Industry Trends 6  The telecommunications service has changed from government regulated to deregulated market with many competitive suppliers of telecommunications services.  Numerous companies now offer businesses and consumers a choice of everything from local and global telephone services to cellular phone services, and Internet access

TECHNOLOGY TRENDS 7  Open Systems  Middleware  Digital Network Technologies  Wireless Technologies

OPEN SYSTEMS 8 Open Systems (like Internet, intranet, and extranet) Information systems that use common standards for hardware, software, applications and networks  Open system with unrestricted connectivity, using Internet networking technologies as their technology platform, are today’s primary telecommunications technology drivers.  e.g. Web browser suites, Internet and intranet servers, HTML Web page editors, and network security firewalls  (all of these technologies are being used in Internet, intranet, and extranet applications)

CONT’D 9  Open System Provides:  Connectivity: Ability of networked computers to easily access and communicate with each other and share information  Interoperability: The ability of an open system to enable end user applications to be accomplished using different varieties of computer systems, software packages, and databases provided by a variety of interconnected networks

Middleware 10  Middleware: is any programming that serves to “glue together” two separate programs  A common application of middleware is to allow a program written for access to a particular database (e.g., DB2) to access another database (e.g., Oracle) without the need for custom coding  It is known as plumbing for IS:  Because it routes data and information transparently between different back-end data sources and end-user applications

Digital Network Technologies 11  Rapid change from analog to digital network technologies  Analog: voice-oriented transmission systems designed to transmit the variable electrical frequencies generated by the sound waves of the human voice  Digital: discrete pulse transmission, (like computer do)  Digital allows:  Higher transmission speed  Larger amounts of information  Greater economy  Lower error rates  Multiple forms of communications on same circuit

WIRELESS TECHNOLOGY 12  Change from copper wire-based media and land-based microwave relay systems to fiber-optic lines and cellular, communications satellite, and other wireless technology.  Fiber-optic transmission, which uses pulses of laser- generated light, offers significant advantage  Reduce size  Reduce installation effort  Vastly greater communication capacity  Much faster transmission speeds  Freedom from electrical interface  Satellite transmission  Ability to transmit massive amount of data, audio, and video over global networks, especially to isolated areas

Internet2 13  Next generation of the Internet  High-performance network that uses an entirely different infrastructure than the public Internet we know today.  It was never intended to replace Internet.  Rather, its purpose is to build a road map that can be followed during the next innovation for the current Internet.  Such as new addressing protocols and satellite-quality streaming video, will likely be deployed to the Internet, but it might take about 10 years.  In use at 200 universities, scientific institutions, communications corporations

Business Value of Telecommunication Networks 14  Use of Internet, intranet, and extranet can:  Cut costs  Shorten business lead times  Shorten response times  Support e-commerce  Improve the collaboration of work-groups  Develop online operation processes All of the above make applications of telecommunications more strategic and vital for business.

Business Value of Telecommunication Networks 15

The Internet 16  Over 46 million servers (2004)  710 – 945 million users (2004)  1 billion users (2007)  No central computer system  No governing body  No one owns it

Internet Service Provider 17  ISP  A company that specializes in providing easy access to the Internet  For a monthly fee, you get software, user name, password and access  ISPs are connected to one another through network access points  Through these connections, one ISP can easily connect to one another to obtain information about the address of a Web site or user node

Cont’d 18  Applications that use the Internet and Internet-based technologies (like intranet and extranet) are less expensive to develop, operate, and maintain than traditional systems  Example, an airline saves money every time customers use its Web site instead of its customer support telephone system  Example, a typical online banking transaction is estimated to cost anywhere from 50%-95% less than its brick-and- mortar counterpart  Example, booking a reservation over the Internet costs 90% less for the airline than booking over the telephone

An Intranet 19  A network inside an organization  That uses Internet technologies (such as Web browsers and servers, TCP/IP protocols, HTML, etc.)  To provide an Internet-like environment within the organization  For information sharing, communications, collaboration and support of business processes  Protected by security measures  Can be accessed by authorized users through the Internet

Extranet 20  Network links that use Internet technologies  To connect the Intranet of a business with the Intranets of its customers, suppliers or other business partners

Telecommunications network 21  Any arrangement where a sender transmits a message to a receiver over a channel consisting of some type of medium

Telecommunications network components 22  Terminals: any input/output device that uses networks to transmit or receive data  Telecommunications Processors: devices that support data transmission and reception  Telecommunications Channels: media over which data are transmitted and received  Computers: all sizes and types  Telecommunications Control Software: programs that control telecommunications activities

Telecommunications network model 23  Wide Area Network (WAN)  Telecommunications network that covers a large geographic area  Local Area Network (LAN)  Connect computers within a limited physical area such as an office, classroom, or building  Virtual Private Network (VPN)  A secure network that uses the Internet as its backbone but relies on firewalls, encryption and other security

Telecommunications network model 24  Client/Server Networks  Clients: End user personal computers or networked computers Interconnected by LANs  Servers: manage networks, Processing shared between clients and servers  Network Computing  Networks are the central computing resource of the organization  Thin clients: network computers and other clients provide a browser-based user interface

Telecommunications network model 25  Peer-to-Peer Network  Networks that connect from one PC to another PC  Common use is the downloading and trading of files

ANY QUESTIONS 26  Refer to Chapter 6 of the book for further reading