BUS1MIS Management Information Systems

Semester 1, 2012

Week 5 Lecture 1

Networks, Telecommunications andMobile Technologies

We are living in an increasingly wireless present ……

…. and hurtling ever faster towards a wireless future.

The tipping point of ubiquitous, wireless, handheld, mobile computing is close.

Baltzan et al. p. 295

Networks, Telecommunications andMobile Technologies

Companies large and small from all over the world are using networked systems, including the Internet, and wireless technologies to gain competitive advantages.

As a business student, you must understand the concepts of network architecture and mobile technology to be able to understand how IT can be used to improve business.

Networks, Telecommunications andMobile Technologies

For example:

Cirque du Soleil - available from the textbook (BDIS) web site)

During the film list all usages of networks, telecommunications and wireless technologies.

Networks, Telecommunications andMobile Technologies

Learning Objectives

Reference: Appendix C, on-line website for the text… and Chapter 7 text

•Compare local area networks (LANs), wide area networks (WANs) and metropolitan networks (MANs)

•List and describe the four components that differentiate networks•Compare the two types of network architectures•Explain topology and the different types found in networks•Describe TCP/IP along with its primary purpose•Identify the different media types found in networks

RAM

ROM

Hard drive Secondary storage

Input devices

Primary storage

output devices

communication devices The `world’

What is a computer network?

Networks

`A computer network is a communications, data exchange, and resource-sharing system created by linking two or more computers and establishing standards, or protocols, so that they can work together’

Networks

Network types

1. Local area networks (LANs)2. Wide area networks (WANs)3. Metropolitan area networks (MANs)

Local area networks typically connect computers and other devices within a small geographical area e.g. a building such as a school, library, private home etc.

Wide area networks typically span a larger geographic area, for example a city, a state or a country. Networks which service large organisations with multiple sites would be classified as a wide area network.

The wide area network that spans the entire globe is the internet

Networks that lie somewhere in between are sometimes referred to as metropolitan area networks. They typically span a city. For example - Swindon, UK

Networks

Network components (other than computers, printers, file servers )

•A protocol [a set of communication rules] •Network interface cards [a piece of hardware that can be plugged into a computer to

allow it to communicate with other computers]•Cables [ the media which connects devices]•Hub (switch or router) [ a piece of hardware that manages the communications

between devices --- the `traffic cop’]

Network performance [see Baltzan et al. p 304 – 6]

Bandwidth refers to the capacity of a network to transmit data i.e. the volume of data that can be transmitted per unit of time.

Broadband refers to high speed internet connections transmitting data at speeds greater than 200 kilobytes per second (Kbps).

NetworksBroadband speeds

The National Broadband Network is expected to deliver download speeds of 100Mbps.

The 3G (mobile phone network) currently delivers 3.6Mbps

Telstra’s 4G network opened in January 20122-40Mbps

Telephone line based

Networks

How are networks differentiated?

… in terms of the network architecture… in terms of the network topology … in terms of the network protocols… in terms of the network media

Networks

How are networks differentiated?

Network architecture

Client-server

A central computer (a `server’) stores data and application files.Other computers in the network (the `clients’) can request applications and data files from the server.

The software which manages all of this (i.e. steering information between devices, managing security and the users) is known as the network operating system (e.g. Novell Netware)

See p.C.5 for the role of packet switching and the router

Networks

How are networks differentiated?

Network architecture

Peer-to-peer

… all computers in the network can share files and use connected devices

No file server

For example, Napster and Kazaa (file sharing of music files across the internet)

Networks

How are networks differentiated?

Network topology … `geometric’ shape

•BUS topology•STAR topology•RING topology

BUS – all devices connected to a central cable (called a bus). Inexpensive and suitable for small networks

STAR – all devices connected to a central device (called a hub). Relatively easy to install and manage, however all data has to go through the hub (potential bottlenecks)

RING – Devices connected to each in a closed loop (each device directly connected to exactly two others). This is an expensive option, offering high band width and networks that can span large distances.

Networks

Network protocols

How are networks differentiated?

When some data is sent over a network it is broken into packets of a set number of characters. A protocol is a standard specifying the format of the packets and rules to be followed during data transmission.

Destination Source Hops 1st data character

2nd data character

3rd data character

4th data character

……….. End of Message

Example of a data packet

Networks

Network protocols

How are networks differentiated?

Two common protocols …

•Ethernet (Local Area network)•Transmission Control Protocol/Internet Protocol (TCP/IP) (Internet)

Networks

Ethernet: physical network interface technology for most LANs

A firewall (hardware and/or software) protects a network form the outside world.

It analyses data/information that is entering or leaving the network.

It looks for `suspicious things’ such as files which contain viruses etc.

See p. 306 -7 Baltzan et al. for a discussion of network security, including the use of passwords and data encryption

Networks

See Appendix C (p c.7 – c.9) for a more detailed description of each

Transmission Control Protocol/Internet Protocol (TCP/IP)

TCP provides the transport functions for data transmission across a network e.g. ensuring that amount of data received matches that sent

IP acts as a `postmaster’ i.e. provides an addressing and routing mechanism for data transmission

IP address – computers on the Internet have an IP address – 194.192.6.6

The world has recently run out of IP addresses.

Networks

An intranet is an internalised portion of the Internet, protected from outside access which allows an organisation to restrict access to application software and information to only its employees.

See p. 116 of Baltzan et al.

Internet (public)

organisation

Intranet (private)firewall

Networks

How are networks differentiated?

Transmission Media

•wire media (twisted pair, coaxial cable, fibre-optic cable)•wireless media

WiMAX (worldwide Interoperability for Microwave Access) is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access

Baltzan et al. p.324

Wireless Networks (WiFi)