Lesson 7 Networks Unit 1—Computer Basics

Computer Concepts BASICS - 2 Objectives Describe the benefits and disadvantages of networks. List and describe the types of networks. List and describe communications hardware. List and describe communications media. Describe the different network topologies. Describe network architecture and protocols.

Computer Concepts BASICS - 3 Introducing Networks A network is a group of two or more computers linked together. Most networks have a server that manages the network resources. Most networks have multiple clients, which are computers that access the server.

Computer Concepts BASICS - 4 Network Benefits Networks provide almost instant communication with other users on the network. Users can share information. Users can share hardware. Users can share software. Users can work on group projects.

Computer Concepts BASICS - 5 Network Disadvantages Data security and unauthorized access are disadvantages of a network. Other disadvantages are Malicious code Network faults Setup and management costs Privacy concerns

Computer Concepts BASICS - 6 Types of Networks Two of the more common types of networks Local area networks (LANs) Wide area networks (WANs)

LANs LANs are usually confined to a small geographical area Most LANs connect personal computers, workstations, and other devices such as printers and scanners 7 Wireless LAN

Computer Concepts BASICS - 8 Wide Area Networks Wide area networks are spread across a city, a state, the country, or the world. Most WANs consist of two or more LANs connected by routers. Some WANs may be configured as intranets or extranets.

Other network types include: Client/server network: Server manages resources Peer-to-peer network: All computers are equal Intranet: Used within an organization Extranet: Specific outside users can access Internet: Global network allows worldwide connection 9

Computer Concepts BASICS - 10 Client/Server vs. Peer-to-Peer

Client/Server Networks In most instances, the client is a software program such as Internet Explorer. The server is hardware and can be one of many types of servers, such as a mail server, a database server, an FTP server, an application server, or a Web server. 11

The network used in this school is a Computer Concepts BASICS HAN 2. PAN 3. LAN 4. WAN

When Internet Explorer displays the class website it is using _________ to retrieve the data from Wordpress. 1. an intranet 2. a client-server network 3. a peer-to-peer network 4. a LAN

When we use the tempfree (J:) drive, we are using 1. the Internet 2. an intranet 3. an extranet

Communication Hardware: Communication hardware devices facilitate the transmitting and receiving of data. Examples are: Modem: Converts analog signals to digital and vice versa Modem Cable modem: Uses coaxial cable Digital subscriber line (DSL): Uses ordinary phone lines T-1: Type of fiber-optic telephone line Wireless: Delivers fast connection speeds 15

Computer Concepts BASICS - 16 Communications Media (cont.) Twisted pair Coaxial Fiber-optic

Computer Concepts BASICS - 17 Other Communications Media IrDA Infrared transmission Requires line of sight Bluetooth Uses radio waves Short distance transmission of about 30 feet WI-FI Wireless fidelity; wireless transmission

Computer Concepts BASICS - 18 Bluetooth Technology

Computer Concepts BASICS - 19 Communications Hardware (cont.) Network interface cards (NICs) All PCs in a LAN must have a NIC. Gateway Links networks using different protocols Router Connects multiple networks and determines the fastest route for sending data over the network

Computer Concepts BASICS - 20 Communications Hardware (cont.) Wireless access point Connects wireless communication devices Hub Receives and sends signals back out

Computer Concepts BASICS - 21 Network Building Blocks (cont.) This figure shows the main components required for data communications: a sending device, a receiving device, a communication path or channel, a device to convert the signal so that the channel can carry it, and the soft- ware to send and receive messages.

Which device would you put inside your computer in order to connect to a network? Computer Concepts BASICS Router 2. Hub 3. Wireless access point 4. NIC

Which device functions like the traffic policeman of a network? Computer Concepts BASICS Router 2. Hub 3. Wireless access point 4. Cable modem

Which device would you use to connect to the Internet at Starbucks? Computer Concepts BASICS Gateway 2. Hub 3. Wireless access point 4. Cable modem

_____ is an example of physical media. Computer Concepts BASICS Twisted-pair cable 2. IrDA 3. Bluetooth 4. Bus topology

The communication medium between a cell phone and a headset is most likely Computer Concepts BASICS Microwaves 2. Bluetooth 3. Fiber-optic 4. IrDA

Network Security Issues Passwords are the most common form of restricting access to data. 27 Establishing and maintaining computer security is necessary to keep hardware, software, and data safe from harm or destruction.

Network Security Issues (continued) Other security measures include: Electronic identification cards Firewalls to protect companies’ networks from external networks Antivirus software A proxy server that acts as an intermediary between a user and the Internet. 28

Network Security Wireless networking is very common, but has many security issues and hackers have found it very easy to access wireless networks. 29

Computer Concepts BASICS - 30 Summary Data communication is the transmission of data from one location to another. A network is a group of two or more computers linked together. The Internet is the biggest network of all. Networks have advantages and disadvantages.

Computer Concepts BASICS - 31 Summary (cont.) A local area network generally is confined to a limited geographical area. A wide area network is made up of several connected local area networks. The two popular types of LANs are the client/server network and peer-to-peer network.

Computer Concepts BASICS - 32 Summary (cont.) Other types of specialized networks include metropolitan area networks (MANs), neighborhood area networks (NANs), personal area networks (PANs), home area networks (HANs), and campus area networks (CANs).

Computer Concepts BASICS - 33 Summary (cont.) You can use a network for information sharing, hardware sharing, software sharing, and as a collaborative environment. The link through which data is transmitted is the communications channel. Transmission media can be either physical or wireless.

Computer Concepts BASICS - 34 Summary (cont.) Physical media includes twisted-pair cable, coaxial cable, and fiber-optic cable. Wireless media includes radio signals, microwaves, and satellites. Most networks consist of a network server and computer clients.

Computer Concepts BASICS - 35 Summary (cont.) Communication devices facilitate the transmitting and receiving of data, instructions, and information. Communication devices include dial-up and cable modems, DSL and ISDN modems, network interface cards, gateways, routers, wireless access points, and hubs.

Computer Concepts BASICS - 36 Summary (cont.) Network interface cards enable the sending and receiving of data between the PCs in a network. A router directs the Internet or network traffic. Physical media includes twisted-pair cable, coaxial cable, and fiber-optic cable. Wireless media includes microwaves, satellites, IrDA, Bluetooth, and Wi-Fi.

Computer Concepts BASICS - 37 Summary (cont.) Network topologies include bus, ring, and star. A protocol is an agreed on set of rules and procedures for transmitting data between two or more devices. The Ethernet protocol is one of the most popular LAN protocols.

Computer Concepts BASICS - 38 Summary (cont.) Token ring is the second most widely used LAN protocol. TCP/IP is a protocol used by both LANs and WANs to connect to the Internet. All computers on a network require an operating system, and networks require network operating systems.