IRM GROUP 2 CHAPTER 2

Information Systems OverviewInformation Systems Overview(COIS 20024)(COIS 20024)

Lecture: Week 5

Networks & Telecommunications

(Information Systems Resources)

12-AUG-2001

Daniel Pun, School of Computing & Information Systems, CQU, Australia 2

Week 5: ResourcesWeek 5: Resources

Study Guide Module 5: Networks & Telecommunications

Textbook Chapter 6: Telecommunications & Networks

Resource Materials Reading 5-1 & 5-2

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ObjectivesObjectives

Describe the concepts of telecommunications networks & their application

Discuss the importance of telecommunications networks for an organisation

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Describe the concepts related to telecommunications networks such as client/server networks, intranets, and extranets etc.

Identify the five categories of components in a telecommunications network

ObjectivesObjectives (cont’d)(cont’d)

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Identify & describe different ways to configure a telecommunications network

Discuss the concepts related to telecommunications protocols & architectures

Describe the major trends in telecommunications


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Identify & give examples of several major ways that organisations are using the Internet for their business activities

Identify & give examples of several ways that the Internet applications provide significant business value to an organisation & its customers


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ObjectivesObjectives



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Communication is the process of sending and receiving verbal and nonverbal messages between, at least, two entities.

Data Communications is the process of electronically sending and receiving data from one place to another over communication links between one or more computer systems and a variety of input/output terminals.

Telecommunications is the transmission of information in any form (e.g., voice, data, text, image) from one place to another using electronic or light-emitting media.

Basic DefinitionsBasic Definitions

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A Communications network is any arrangement where a sender transmits a message to a receiver over a medium.

A Telecommunications network is any arrangement of interconnected computers and peripheral devices to process and exchange data and information.

Basic Definitions Basic Definitions (cont’d)(cont’d)

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Twisted Pair Coaxial Cable Fiber Optics Terrestrial

Microwave

Communication Satellites

Cellular Technologies

Wireless LAN

Telecom Communication MediaTelecom Communication Media

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Modems Multiplexers Internetwork

Processors Switches Routers Hubs Gateways

Fire walls

Network Operating System

Telecommunications Monitor

Middleware Network Management

Software

Telecom Processors & SoftwareTelecom Processors & Software

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Objectives Objectives (cont’d)(cont’d)



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Connectivity: allows exchange of data & information

Keeps the various system elements working together effectively and efficiently by exchanging data and information

Allows informed decisions to be made

Better management of organisational resources and activities

Better decisions and higher productivity

Improved services to customers and clients

Increased competitive advantages

Importance of Telecom for Orgs.Importance of Telecom for Orgs.

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Wide Area NetworksWide Area Networks

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NetworkServer

Shared Database and

Software Packages

SharedPrinter

PCPC

PC PC PC

Internetwork Processor to Other Networks

Local Area NetworksLocal Area Networks

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Router

IntranetServer

Host System

IntranetServer

TheInternet

Fire wall

Fire wall

RouterExtranet

Other E-Business NetworksOther E-Business Networks

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Virtual Private Networks (VPNs)Virtual Private Networks (VPNs)

Many organizations use VPNs to establish secure intranets and extranets. A VPN is a secure network that uses the Internet as its main backbone network, but relies on fire walls and other security features. In this manner, a company can use the Internet to establish secure intranets with remote branch offices and secure extranets between itself and business partners and customers.

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NetworkServer

Host SystemSuperserver

Client

User InterfaceApplication Processing

Application ControlDistributed Database

Central database controlHeavy duty processing

Server Server

NetPC

Browser-basedUser Interface

Web OSApplication Software

Application

DBMS

DB

Client/Server NetworksClient/Server Networks

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Client/Server Networks Client/Server Networks (con’t)(con’t)

Client/Server Networks are the predominant information architectures used in business today. In a client/server network, the end user PC is the client. These are interconnected by local area networks, and share application processing with network servers. This is sometimes called a two-tier client/server architecture. Local area networks can also be interconnected with other networks, including host systems and superservers.

Client/server architectures are seen as more economical and flexible than legacy mainframe systems.

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TelecommunicationsSoftware

1

2 3

4

52

PCs, NCs, and Other Terminals

ComputersTelecommunicationsChannels and Media

TelecommunicationsProcessors

Components in a Telecom NetworksComponents in a Telecom Networks

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Components in a Telecom Networks Components in a Telecom Networks (cont’d)(cont’d)

Like any communications model, a telecommunications network connects a sender to a receiver over a channel for sharing messages. The basic components of a telecommunications network are:

Terminals: These are networked microcomputer workstations or video input/output stations that provide the sending and receiving endpoints for the network.

Telecommunications Processors: These are specialized hardware components that support data transmission and reception between terminals and computers. Examples include modems, routers, and switches.

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Components in a Telecom Networks Components in a Telecom Networks (cont’d)(cont’d)

Telecommunications Channels and Media: A channel connects two or more parties in a network. Media are the particular way a channel is connected. Telecommunications channels use combinations of media such as copper wires, coaxial cables, fiber optic cables, and microwave carriers to transmit information.

Computers: All sizes and types of computers can and are connected to telecommunications networks. Typical arrangements include using a mainframe as a host for the network, a minicomputer as a front-end processor, with a dedicated microcomputer as a network server to a smaller local group of networked microcomputer workstations.

Telecommunications Control Software: Consists of programs that control telecommunications activities and manage the functions of telecommunications networks. Examples include network operating systems, browsers and telecommunications monitors.

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Network TopologiesNetwork Topologies

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Network Topologies Network Topologies (cont’d)(cont’d)

There are three basic topologies used in telecommunications networks:

Star Topologies: Connect end user computers to a central computer. Used for centralizing processing. Since the network is reliant on the performance of the central computer, this topology is less reliable than either ring or bus. If the central computer fails, the network fails. May be used in WANs and LANs.

Ring Topologies: Connect end user computers together in a ring on a more equal basis. It is more reliable and has no single point of failure. Used mostly in LANs.

Bus Topologies: Connect end user computers on a common channel. Used commonly in business LANs. It also has no single point of failure. It is cheaper than ring networks, but sometimes less reliable.

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Application Layer

Presentation Layer

Session Layer

Transport Layer

Network Layer

Data Link Layer

Physical Layer

SevenLayers ofthe OSICommunicationsArchitecture

Network Protocols: The OSI ArchitectureNetwork Protocols: The OSI Architecture

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Network Protocols: The OSI Architecture Network Protocols: The OSI Architecture (cont’d)(cont’d)

The International Standards Organization (ISO) has developed a seven-layer Open Systems Interconnection (OSI) model to serve as a standard model for network architecture.

Application Layer provides communications services for end user applications.

Presentation Layer provides appropriate data transmission formats & codes.

Session Layer supports the accomplishment of telecommunications sessions.

Transport Layer supports the organization and transfer of data between nodes in the network.

Network Layer provides appropriate routing by establishing connections among network links.

Data Link Layer supports error free organization and transmission of data in the network.

Physical Layer provides physical access to the telecommunications media in the network.

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Application orProcess Layer

Internet Protocol (IP)

Host-to-Host Transport Layer

Network Interface

Physical Layer

ApplicationLayer

PresentationLayer

SessionLayer

TransportLayer

NetworkLayer

Data LinkLayer

PhysicalLayer

OS

I Mo

del

The Internet’s TCP/IPThe Internet’s TCP/IP

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More electronic commerce, enterprise collaboration,online business operations and strategic advantage in markets

More vendors, carriers, alliances, and network services, accelerated by deregulation & Internet growth

Extensive Internet, interconnected local & global digital networks, improved transmission channels

Industry Trends

Technology Trends

Application Trends

Trends in TelecommunicationsTrends in Telecommunications

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E-mail

InternetRelayChat

Telnet

Search Engines

E-CommerceFile

TransferProtocol (FTP)

Popular Uses of the

Internet

Internet ApplicationsInternet Applications

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By 1995, over 1.5 million host networks on the Internet belonged to businesses. Businesses on the Internet are there in part to take advantage of the easy, worldwide communications available through E-mail and file transfer protocols (FTPs). But business is also on the Net to help shape the network as a channel for conducting business transactions -- buying and selling goods and services in cyberspace to distant customers linked by computers and modems. Business uses of the Internet are rapidly developing in areas such as electronic commerce.

Business Use of the InternetBusiness Use of the Internet

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Overcome Geographic Barriers: Capture information about business transactions from remote locations.

Overcome Time Barriers: Provide information to remote locationsimmediately after it is requested.

Overcome Cost Barriers: Reduce the cost of more traditional means of communications.

Overcome Structural Barriers: Support linkages for competitive advantage.

Business Value provided by the Internet applicationsBusiness Value provided by the Internet applications

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Organizations are becoming internetworked enterprises that use the Internet, intranets, and other telecommunications networks to support E-Business.

Telecommunications has entered a deregulated and fiercely competitive environment with many vendors, carriers, and services

A major trend is towards pervasive use of the Internet and its technologies to build interconnected enterprise and global networks.

SummarySummary

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The major components of any telecom network are: Terminals, Telecommunications processors, Communication channels, Computers, and Telecommunications software.

There are several basic types of telecomm networks, including wide area networks (WANs) and local area networks (LANs).

SummarySummary (cont’d)(cont’d)

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Key telecommunications network alternatives include telecommunications media, processors, software, channels, and architectures.

SummarySummary (cont’d)(cont’d)

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Information Systems for Enterprise Collaboration

(Information Systems Applications)

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IRM GROUP 2 CHAPTER 2