Extended Learning Module D

Network Basics

Main Map

n Peer-to-Peer Home Networks

n Internet Access

n Business Networks

n LANs, MANs, WANs, and Communications Media

n Communications Service Providers

Introduction

n Whether you are

t Surfing the web

t Accessing software at school or

t Sending email

Your computer is part of a network

Introduction

n Computer network - two or more computers connected so that they can communicate with each other and share information, software, peripheral devices, and/or processing power.

Introduction
Basic Principles of Networks

n Each computer must have a network card.

n A network has at least one connecting device.

n There must be communications media connecting the network hardware devices.

n Each computer must have software that supports the movement of information.

Introduction

Peer-to-Peer Home Networks

n Peer-to-Peer Home Networks P

n Internet Access

n Business Networks

n LANs, MANs, WANs, and Communications Media

n Communications Service Providers

Peer-to-Peer Home Network

Peer-to-Peer Home Network

Peer-to-Peer Home Network
Home Network Components

n Network interface card (NIC) - an expansion card or a PC Card that connects your computer to a network and provides the doorway for information to flow in and out.

Peer-to-Peer Home Network
Home Network Components

n Ethernet card - the most common type of network interface card.

Peer-to-Peer Home Network
Home Network Components

n Network hub - a device that connects multiple computers into a network with only one communications link at a time.

n Switch - a device that connects multiple computers into a network in which multiple communications links can be in operation simultaneously.

Peer-to-Peer Home Network
Home Network Components

Figure D.1
Hub, Switch, and Router as Roadway Intersections
page 428

Peer-to-Peer Home Network
Home Network Components

n Router - a device that acts as a smart hub connecting computers into a network, and it also separates your network from any other network it’s connected to.

Peer-to-Peer Home Network
Home Network Components

Figure D.2
Typical Home Network
page 429

Peer-to-Peer Home Network
Home Network Components

n Firewall - software and/or hardware that protects a computer or network from intruders.

n Cat 5, or Category 5 cable
- a better-constructed
version of the phone twisted-
pair cable.

Peer-to-Peer Home Network
Wireless Access to Your Home Network

n Wireless network access point or wireless access point - a device that allows computers to access a wired network using radio waves.

Peer-to-Peer Home Network
Wireless Access to Your Home Network

n WiFi, Wireless Fidelity, or IEEE 802.11b - a way of transmitting information in wave form that is reasonably fast and is often used for notebooks.

n Bluetooth technology - provides entirely wireless connections for all kinds of communication devices.

Peer-to-Peer Home Network
Home Network with Existing Phone Wiring

n Home PNA (Home Phone line Networking Alliance) - allows you to network your home computers using telephone wiring.

n PNA adapter card - an expansion card that you put into your computer to act as an doorway for information flowing in and out.

Peer-to-Peer Home Network
Home Network with Existing Phone Wiring

Figure D.3
Home PDA Network page 430

Internet Access

n Peer-to-Peer Home Networks

n Internet AccessP

n Business Networks

n LANs, MANs, WANs, and Communications Media

n Communications Service Providers

Internet Access

Ways to Access the Internet at Home

n Telephone line and a telephone or dial-up modem.

n Telephone line and a Digital Subscriber Line (DSL) modem.

n Cable TV line and a cable modem.

n Satellite dish and a satellite modem.

n Provider that offers wireless connection for your notebook.

Internet Access

n Broadband - a high-capacity telecommunications pipeline capable of providing high-speed Internet service.

Internet Access
Telephone or Dial-Up Connection

n Telephone modem - a device that connects your computer to your phone line so that you can access another computer or network.

Internet Access
Digital Subscriber Line (DSL)

n Digital Subscriber Line (DSL) - a high-speed Internet connection using phone lines, which allows you to use your phone for voice communications at the same time.

Internet Access
Cable Modem

n Cable modem - a device that uses your TV cable to deliver an Internet connection.

Internet Access
Internet over Satellite

n Satellite modem - a modem that allows you to get Internet access from a satellite dish.

Internet Access
Internet Access on Multiple Computers

n Network address translator (NAT) – swaps messages between the private, internal IP addresses, and the public IP address, when moving information between the Internet and network computers.

Internet Access
Wireless Internet Connection

n Wireless Internet service provider (wireless ISP) - does the same job as standard Internet service providers except that you don’t need a wired connection for access.

Internet Access
Wireless Internet Connection

n Personal digital assistant (PDA) - a small hand-held computer that helps you surf the Web and perform simple tasks such as note taking, calendaring, appointment scheduling, and maintaining an address book.

t Palms and Handspring - run on the Palm Operating System

t PocketPCs - run on Pocket PC OS

Business Networks

n Peer-to-Peer Home Networks

n Internet Access

n Business Networks P

n LANs, MANs, WANs, and Communications Media

n Communications Service Providers

Business Networks

n Client/server network - a network in which one or more computers are servers and provide services to the other computers which are called clients.

Business Networks
Client/Server: A Business View

n Client/server networks differ according to three factors:

t Where the processing for the presentation of information occurs.

t Where the processing of logic or business rules occurs.

t Where the data management component (DBMS) and information (database) are located.

Business Networks
Client/Server: A Business View

Figure D.8
Model 5: A Personal Data Warehouse in a Client/Server Implementation
page 436

Business Networks
Client/Server: A Business View

Business Networks
Client/Server: A Business View

The Five Models of Client/Server

n Distributed Presentation

t The server handles almost all functions, including a major portion of the presentation.

n Remote Presentation

t The client handles all presentation functions.

n Distributed Logic

t The server handles all data management and the client handles all presentation formatting, and the logic processing is shared.

Business Networks
Client/Server: A Business View

n Remote Data Management

t The server handles data management only, and the client processes business rules and formats the presentation of results.

n Distributed Data Management

t The client handles all presentation formatting and business rule processing, and both the server and client share data management duties.

Business Networks
Client/Server: A Business View

Figure D.9
Five Models for Client/Server Implementation
page 438

Business Networks
Client/Server: A Business View

Business Networks
Client/Server: A Physical View

n There are many physical implementations of client/server networks

n Conceptually, large networks work on the same principles as small ones

Business Networks
Client/Server: A Physical View

n You still need

t Network cards

t Hubs

t Switches

t Routers

t Communications media and

t Network operating systems

Business Networks
Client/Server: A Business View

Figure D.10
Model 3: Client/Server Implementation for Employee Pay Raises
page 440

Business Networks
Client/Server: A Physical View

n Communications protocol (protocol) - a set of rules that every computer follows to transfer information.

Business Networks
Client/Server: A Physical View

Figure D.11
A Typical Client / Server Network for a Medium-Sized Business
page 441

LANs, MANs, MANs and Communications Media

n Peer-to-Peer Home Networks

n Internet Access

n Business Networks

n LANs, MANs, WANs, and Communications Media P

n Communications Service Providers

LANs, MANs, WANs, and Communications Media
Classification of Networks by
Geographic Distance

n Local area network (LAN) - covers a limited geographic distance, such as an office, building, or a group of buildings in close proximity to each other.

n Municipal area network (MAN) - covers a metropolitan area.

n Wide area network (WAN) – covers a large geographic distances, such as a state, a country, or even the entire world.

LANs, MANs, WANs, and Communications Media
Telecommunications Media: The Paths That Carry Information

n Communications media - the paths, or physical channels, in a network over which information travels.

n Wired communications media - transmit information over a closed, connected path.

n Wireless communications media - transmit information through the air.

LANs, MANs, WANs, and Communications Media
Telecommunications Media: The Paths That Carry Information

n Wired Communications Media include:

t Twisted-pair cable

t Coaxial cable

t Optical Fiber

LANs, MANs, WANs, and Communications Media
Telecommunications Media: The Paths That Carry Information

n Wireless Communications Media Include:

t Microwave

t Satellite

t Infrared

LANs, MANs, WANs, and Communications Media
Bandwidth

n Bandwidth - refers to the amount of information that a communications medium can transfer in a given amount of time.

LANs, MANs, WANs, and Communications Media
Wired Communications Media

n The simplest type of twisted-pair phone cabling (Cat 1) provides a slow, fairly reliable path for information at up to 64 kilobits per second (Kbps).

n A better type (Cat 3) provides up to 10 megabits per second (Mbps).

LANs, MANs, WANs, and Communications Media
Wired Communications Media

n Coaxial cable (coax) - one central wire surrounded by insulation, a metallic shield, and a final case of insulating material.

n Coax is the kind of cable that
delivers cable television
transmissions and also carries
satellite TV from the dish to
your house.

LANs, MANs, WANs, and Communications Media
Wired Communications Media

n Optical fiber - uses a very thin glass or plastic fiber through which pulses of light travel.

LANs, MANs, WANs, and Communications Media
Wireless Communications Media

n Wireless communications media radiate information into the air, either very narrowly beamed or in many directions like ripples from a pebble tossed into a pond.

LANs, MANs, WANs, and Communications Media
Infrared and Omnidirectional Microware for Short Distances

n Infrared - a wireless communications medium that uses radio waves to transmit signals or information.

n Microwave transmission - a type of radio transmission.

t Bluetooth

t WiFi

LANs, MANs, WANs, and Communications Media
Directional Microware for Medium Distances

n Repeater - a device that receives a radio signal, strengthens it and sends it on.

LANs, MANs, WANs, and Communications Media
Satellites for Long Distance

n Communications satellites - microwave repeaters in space.

Communications Service Providers

n Peer-to-Peer Home Networks

n Internet Access

n Business Networks

n LANs, MANs, WANs, and Communications Media

n Communications Service Providers P

Communications Service Providers

n Communications service providers - third parties who furnish the conduit for information.

n Public network - a network on which your organization competes for time with others.

Communications Service Providers

Figure D.14
Comparison of Types of Network Ownership
page 446

Communications Service Providers

n Private network - communications media that your organization owns or exclusively leases to connect networks or network components.

n Value-added network (VAN) - a semipublic network that provides services beyond the movement of information from one place to another.

Communications Service Providers

n Virtual private network (VPN) – uses software to establish a secure channel on the Internet for transmitting data.

Communications Service Providers
Key Considerations for Communications Media

n To determine the most appropriate communications medium, you must consider:

t Capacity

t Reliability

t Cost

t Distance

t Mobility

Summary
Student Learning Outcomes

n Identify and describe the four basic concepts on which networks are built.

n Describe how to set up a small peer-to-peer network at home.

n Compare and contrast the various Internet connection possibilities.

n Describe client/server business networks from a business and physical point of view.

Summary
Student Learning Outcomes

n Define and compare local area networks (LANs), municipal area networks (MANs), and wide area networks (WANs).

n Compare and contrast the types of communications media.

Summary
Assignments & Exercises

n Investigate Cell Phone Technology

n Find out about Personal Digital Assistants

n What Are the Internet Access Options in Your Area?

n Investigate Building Your Own Home Network

n Investigate Satellite Radio