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PowerPoint Presentation to Accompany Chapter 9 Networks & Communications Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objectives 1. Discuss the importance of computer networks. 2. Compare different types of LANs and WANs. 3. List and describe the hardware used in both wired and wireless networks. 4. List and describe the software and protocols used in both wired and wireless networks. 5. Explain how to protect a network. Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objective 1: Overview From Sneakernet to Hotspots 1. Define computer network and network resources 2. Discuss the importance of computer networks 3. Differentiate between peer-to-peer networks and client-server networks Key Terms Client Client-server network Computer network Homegroup Network resource Visualizing Technology Peer-to-peer network Server Workgroup Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Computer Networks A computer network is two or more computers that share resources Network resources can be software, hardware, or files Computer networks save time and money and increase productivity. Computer Network Types A peer-to-peer (P2P) network is one in which each computer is considered equal. A client-server network is one that has at least one server at its center. Computer Network Types Peer-to-Peer (P2P) Each device can share resources with Every other device • No centralized authority • Each computer belongs to a workgroup • Do not need to connect to the Internet • Most found in homes and small businesses • Simplest type of network • Do not need network operating system • All computers must be on to access resources Peer-to-Peer Networks Each node connected to the network can communicate directly with each other: Peers Share peripheral devices: Printers Scanners When printing, a computer on a P2P network doesn’t have to go through the computer connected to the printer. It can communicate directly with the printer © 2008 Prentice-Hall, Inc. 7 Peer-to-Peer Networks Because they are simple to set up, P2P networks are the most common type of Home network. Computers in a P2P network belong to a workgroup. This allows you to share and remotely access files on a Windows network. © 2008 Prentice-Hall, Inc. 8 Peer-to-Peer Networks Most P2P networks are found in homes or small businesses. A peer-to-peer network doesn’t require a NOS. While your personal OS has networking features, the files and services that are shared between your home computers aren’t centralized. © 2008 Prentice-Hall, Inc. 9 Peer-to-Peer Networks Windows makes setting up a home network an easy task. When you add a new computer to your home and turn it on, Windows will automatically detect the other devices that are already on your network. Windows Network and Sharing Center enables you to view and configure your network settings. The biggest problem with this type of network is that the computer that’s sharing a resource must be turned on and accessible by the other computers in the network. © 2008 Prentice-Hall, Inc. 10 Peer-to-Peer Networks Windows includes a simple networking feature called a Homegroup. Consists of the computers on your home network running Windows 7 or higher that are configured with the same homegroup password. Once you create a homegroup, Windows will create a password that you can use to join all your other Windows computers to the homegroup. Members of a homegroup automatically share their picture, music, and video libraries and printers with each other without and additional configuration on your part. © 2008 Prentice-Hall, Inc. 11 Peer-to-Peer Networks If you have computers running other versions of Windows or Linux or Mac computers, then you will need to use a workgroup to share resources between them. Setting up the shares in a workgroup is not difficult but takes a bit more work than setting up a homegroup. Computers in a workgroup need to have the same workgroup and account information configured. © 2008 Prentice-Hall, Inc. 12 Computer Network Types Client-Server Network Has a least one server at its center • Provides a way to centralize network management, resources, and security • Users log in to a network and are granted access based on that login • A server is a multiuser computer system that runs on a network operating system • Clients are the PCs and other devices that connect to the server Client/Server Networks Most networks with 10 or more nodes are client/server Contains two different types of computers Client computers Computers on which Users accomplish specific tasks and make specific requests Server computers Computers that provide information or resources to the client computers 14 Client/Server Networks Server computers A multiuser computers system that runs a NOS and provides central administration for functions on the network Printing E-mail File Internet access © 2008 Prentice-Hall, Inc. 15 Client/Server Networks As the name implies, both client software and server software are needed on a client-server network. The client software makes requests, and the server software fulfills them. A domain is a network composed of a group of clients and servers under the control of one central security database on a special server called the domain controller. 16 Client/Server Networks You only need to log in to the domain once to have access to all the servers in the domain. The security database includes your user information: Who you are; What your password is; What your access and restrictions are. 17 Client/Server Networks Clients log in to a server and request access to resources. For many types of servers, a special client is needed. When you use your Web browser to access your e-mail, it serves as an e-mail client. 18 Client/Server Networks The browser can also act as: An FTP client when you download a file; A database client when you access your bank transactions; An HTTP client when you access a Web page. Other client software you may use includes VPN software, desktop, e-mail programs, instant messaging/chat programs, and even video and photo software that include an upload feature 19 Client/Server Networks Server software is also known as a network operating system. A network operating system (NOS) is a multiuser operating system that controls the software and hardware that runs on a network. 20 Client/Server Networks It allows multiple computers (clients) to communicate with the server and each other, to share resources and security and provides services such as: File and print services; Communication services; Internet and e-mail services; Backup services; Database services to the client computers. 21 Client/Server Networks Servers are classified by the type of services they provide. Some common services are: File and print services; E-mail; Database; Web; Chat; Audio/video; Applications. 22 Client/Server Networks The Internet is a Client/Server Network. When your computer is connected to the Internet, it is functioning as a client computer. When connecting to the Internet through an ISP, your computer connects to a server computer maintained by the ISP. The server “serves up” resources to your computer so that you can interact with the Internet 23 Computer Networks Computer network Two or more computers Share resources Save time Save money Increase productivity Network resources Software Hardware Files Homegroup Simple networking feature Used to network a group of Windows computers Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Select a computer network that you use (school, home, work). Is this a P2P or client-server network? How do you connect to it? What resources do you access/share on this network? Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objective 2: Overview LANs and WANs 1. Compare different types of networks 2. Differentiate between small and large networks Key Terms CAN Cellular network Ethernet LAN MAN PAN Visualizing Technology SAN Topology VPN WAN WLAN Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Networks Small Networks Large Networks LAN: Local area PAN: Personal area WLAN: Wireless LAN WAN: Wide area network VPN: Virtual private network CAN: Campus area network MAN: Metropolitan area network SAN: Storage area network Cellular networks Small Networks LAN (local area network): A network that has all connected devices or nodes located in the same physical location. A home network is a peer-to-peer LAN. A business LAN is more likely a client-server network and consists of computers, printers, and servers as well as the network hardware that connects them. Devices on a LAN are connected using switches. Small Networks PAN (personal area network): A LAN that consists of devices connected by Bluetooth, such as a PDA and a computer. Also called piconet. Bluetooth is designed to be easy to use, allowing devices to talk to each other securely over short distances. Each device in a piconet can connect to up to seven other devices at a time. Mice, keyboards, interactive white boards, headsets, cell phones, PDAs, cameras, media players, video game consoles, printers. Small Networks WLAN (wireless LAN): A LAN that uses WiFi to transmit data. WiFi has a much larger range, higher speeds, better security, and supports more devices than Bluetooth. More expensive and complicated to set up. Large Networks WAN (wide area network): A network that spans multiple locations and connects multiple LANs over dedicated lines using routers – devices that connect two or more networks together. A college that has multiple campuses would need to use WAN connections between them. WAN technologies are slower and more expensive than LAN technologies. At home, the WAN you connect to is the Internet, and the port on your router that connects to the modem is labeled WAN port, distinguishing it from the LAN ports your other devices are connected to. Large Networks VPNs (virtual private networks): creates a private network through the public network, the Internet, allowing remote users to access a LAN securely without needing dedicated lines. This is much less expensive and more practical for businesses, and in some cases, a VPN even replaces the need for dedicated lines completely. VPNs use encryption to ensure the data is secure as it travels through the public network. Large Networks CAN (campus area network): A hybrid of LANs and WANs connected using routers. In a business that is too large and has too many computers to manage a single LAN practically, there may be multiple LANs located in the same location. These LANs are connected to each other using routers, technically making them WANs. MAN (metropolitan area network): Covers a single geographic area. A wireless network in Philadelphia provides access over much of the city. Large Networks SAN (storage area network): Companies that have massive amounts of information to move and store have a network between the data storage devices and the servers on a network, making the data accessible to all servers in the SAN. Normal users are not part of the SAN but are able to access the information through the LAN servers. Large Networks Cellular networks: Use cell towers to transmit voice and data over long distances. Modern 4G networks have speeds that have made these networks a practical way for people on the move to connect to network resources, including the Internet and corporate VPNs from almost anywhere in the world. LAN Topologies A home LAN uses the same Ethernet standards and equipment used in larger business networks. Standards – specifications that have been defined by an industry organization – ensure that equipment made by many different companies work together. The Ethernet standard defines the way data is transmitted over a LAN. Network data transmission speed is measured in bits per second. Ethernet Standards are specifications and equipment used in larger business networks. A home LAN uses the same Ethernet standards and equipment used in larger business networks. Ethernet is a standard that defines the way data is transmitted over a LAN. Although there are other network standards, Ethernet is by far the most widely implemented. Standards are important because they assure that equipment that is made by different companies will be able to work together. Ethernet Ethernet networks transmit signals over twistedpair cable, fiber-optic cable, and WiFi at data transmission speeds ranging from 10 Mbps to 10 Gbps. The maximum speed depends on the type of media and capability of the network hardware on the LAN. Most home networks use100 Mbps Ethernet. Regardless if a small or large network, both use the same Ethernet standards and equipment Networks The physical layout of a LAN is called its topology. The devices (nodes) on the LAN can be connected in three physical layouts: Bus Ring Star Networks Bus: The nodes are all connected via a single cable. The data travels back and forth along the cable, which is terminated at both ends. Ring: The devices are connected to a single cable, but the ends of the cable are connected in a circle, and the data travels around the circle in one direction. Star: Every node on the network is attached to a central device such as a switch or wireless access point. This connection device allows nodes to be easily added, removed, or moved, without disrupting the network. Networks Computer networks range from two PCs sharing a printer to large enterprise networks to the Internet. The larger and more complex networks require more hardware, configuration, and expertise to manage, but they all have the same basic purpose – to share resources. Make a list of networks that you use. Include home, cellular, work, and school networks. Label each as LAN, WAN, or one of the others described in this article. List the devices you use to connect to each. What resources do you access? Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objective 3: Overview The Networking Hardware Store 1. List and describe the hardware used in wired networks 2. List and describe the hardware used in wireless networks Key Terms Ad hoc network Firewall Infrastructure wireless network Modem Network adapter ONT Visualizing Technology Router Switch WAP Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Hardware Used in Networks A network adapter is a communications device used to establish a connection with a network. The network hardware are the physical devices needed to create the network. Network Adapters WIRED Each device that connects to a network must have some type of network adapter. Most PCs come with a built-in Ethernet adapter, also called RJ-45. Looks like a slightly larger phone jack. The cable used for this type of connection is called twistedpair, Ethernet cable, or Cat-5 (6). The other end of the cable will plug into a wall jack, a switch, a router, or a modem Network Adapters WIRED There are several advantages to using a wired network connection, including speed, location, and security. Network speed is measured in bits per second. Most home Ethernet connections use FastEthernet connections, which equal 100Mbps. No wireless technology can currently reach the 1Gbps speed, but some can equal or exceed the 100 Mbps speed. Network Adapters WIRED Another advantage is that a wired connection is less subject to interference and can travel long distances without slowing. A wireless connection that is 150 Mbps at close range might drop to less than half that speed at a distance of 300 feet. Buildings and other structures can slow or even prevent a wireless connection from working. Network Adapters WIRED Finally, a wired connection is more secure than a wireless connection, especially if the wireless connection is not configured with strong security settings. Network Adapters WIRELESS There are several types of wireless network adapters. The Wi-Fi networks found in homes and public hotspots use the IEEE 802.11 standards. The Wi-Fi Alliance certifies wireless devices to ensure interoperability. Most notebook computers and tablets come with a built-in wireless adapter. A USB wireless adapter can easily be connected to a desktop, smart TV, or game console that does not have one built in. Network Adapters WIRELESS Wireless printers can be connected directly to a network, eliminating the need to be shared from an individual computer. When two wireless devices connect to each other directly, they create an ad hoc network. In an infrastructure wireless network, devices connect through a wireless access point. At home, a wireless access point is built into your wireless router. Network Adapters Wired Wireless Pros Cons 1. Maximum speed 1,000 Mbps or 1 Gbps 2. Fast-Ethernet is 100 Mbps 3. Less interference 4. More secure working environment Lack of portability Pros Portability Cons 1. 2. 3. 4. Cannot reach the 1 Gbps speed Prone to interference Buildings and distance can slow or prevent connection Needs to be configured with strong security settings Network Hardware A business network consists of routers, switches, wireless access points, and firewalls (all in one in a home network). The first device on a network is usually the device that connects to the Internet. If you use a dial-up connection, this is a traditional modem (modulator-demodulator). Cable and DSL have special digital modems. FIOS has an optical network terminal (ONT). You can connect your computer directly to a modem or ONT, but you can share the connection with other devices more easily with some basic network hardware. Network Hardware A business network consists of routers, switches, wireless access points, and firewalls. A router is a device that connects two or more networks together ( your home network and the Internet). A router uses address information to correctly route the data packets it receives. In a home network, the router is a convergence device that serves several functions. It shares the Internet connection; Provides IP addresses to the other network devices; Provides security for your network. Network Hardware Routers make up the backbone of the Internet and are responsible for sending the data packets along the correct route to their destination. Home routers also include a built-in switch with several ports to connect multiple devices and can also serve as a wireless access point. Network Hardware A switch is a device that connects multiple devices on a LAN and can also serve as a wireless access point (WAP). Within the network, a switch uses address information to send data packets only to the port that the appropriate device is connected to. Network Hardware To set up a WiFi network, you’ll need a wireless access point. A wireless access point (WAP) is a device that allows wireless devices to join a network much like a switch. It can be built into a router or it can be a separate device. In a large wireless network, there may be many WAPs installed. Network Hardware A firewall is a device that blocks unauthorized access to a network. There are both hardware firewalls and software firewalls. Such as the software firewall included with your operating system. A hardware firewall may be part of a router or stand-alone device. Network Hardware Firewalls can check both outgoing and incoming data packets. A firewall can be configured with filters to allow/deny various kinds of traffic. Firewall filters can be based on an: IP address; Protocol type; Domain names; Other criteria. Incoming packets that try to access restricted data will be denied access to the network. Networks The image shows a home network that includes both wired and wireless devices. Network Hardware The larger and more complex a network, the more hardware is necessary to assure the flow of data. These devices work together to transmit and filter data packets around the network and eventually to their destination. Without the network hardware, computers could not connect to each other. Open the Network Connections window as described in this article. What adapters are installed on your computer? What type of networks do they connect to? Which of them are connected now? Include a screen shot in the window. Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objective 4: Overview The Softer Side 1. List and describe the software used in both wired and wireless networks 2. List and describe the protocols used in both wired and wireless networks Key Terms Domain IP NOS Protocol TCP TCP/IP protocol stack Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Software Used in Networks Software and protocols allow networks to communicate with and understand each other. Network operating systems, communication software, and protocols make a network work. P2P Software No special software is required to create a simple P2P network Modern desktop OSs have networking capabilities built into them When Windows is installed on a computer, it includes a feature called Clients for Microsoft Networks, which allows it to remotely access files and printers on a Microsoft network P2P Software Using the workgroup feature of Windows allows you to share and remotely access files on a Windows network. OS X includes Windows File Sharing , and its network discovery tool should locate your Windows computer automatically in Finder. Client-Server Software Both client software and server software are needed on a client-server network The client software makes requests, and the server software fulfills them In a network running Microsoft Server NOS, Windows clients do not need any special client software for file and print services Client-Server Software DOMAIN CONTROLLER They use the same Client for Microsoft Networks used in peer-to-peer networks to connect to the servers. A domain is a network composed of a group of clients and servers under the control of one central security database on a special server called a domain controller You only need to log in to the domain once to have access to all the servers in the domain In a network with multiple servers, you don’t need Io log in to each one individually. The domain security database includes your user information Who you are, what your password is, and what your access and restrictions are. Client-Server Software CLIENT SOFTWARE For many types of servers, a special client software is needed. • When you use a Web browser to access your e-mail, it serves as an e-mail client • When you download a file, it acts as an FTP client • When you access a database, it acts as a database client • When you access a Web page, it acts as an HTTP client Client-Server Software SERVER SOFTWARE Server software, also known as a network operating system (NOS), is a specialized operating system that controls the software and hardware on a network. It allows multiple client devices to communicate with the server and each other to: Share resources; Run applications; Send messages. A NOS centralizes resources and security and provides services such as file and print services, communication services, Internet and email services, and backup and database services to the client computers. Client-Server Software SERVER SOFTWARE Servers are classified by the type of services they provide Some common services include file and print services, e-mail, database, Web, chat, audio/video, and applications Whenever you log in to a Web site like Facebook, you are connecting to a server. Network Protocols Network hardware enables devices to connect to each other, and network protocols enable them to communicate. Protocols define the rules for communication between devices. These rules determine how data is formatted, transmitted, received, and acknowledged. Without protocols, devices could be physically connected and still unable to communicate. Network Protocols Network protocols: Define how a conversation between devices begins. Define how devices converse Define the method to end an electronic conversation. Network Protocols Although there are hundreds of different protocols, the most important ones belong to the TCP/IP protocol stack The basic communication language of the Internet. A suite of protocols that define everything from how to transfer files (FTP) and webpages (HTTP) to sending (SMTP) and receiving (POP) email. Network Protocols TCP stands for Transmission Control Protocol. Responsible for ensuring that data packets are transmitted reliably. IP stands for Internet Protocol. Responsible for addressing and routing packets to their destination. Both pieces are needed for data to move between devices. Network Protocols Make a list of networks that you use. Include home, cellular, work, and school networks. List the software clients that you use to connect to each. What resources do you access? Do you use different clients to access different resources? Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Objective 5: Overview Protecting Your Network 1. Explain how to protect a network using software, strong passwords, firewalls, and maintenance Key Terms Piggybacking Wardriving Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Network Protection Layer 1 Hardware-based firewall via router Layer 2 Strong passwords Layer 3 Software-based firewall, antivirus and anti-malware Layer 4 Keep system up-to-date and secure Network Protection Layer 1 – The Fence: The fence is the hardware at the access point to your network. The firewall examines the data packets as they enter or leave your network and will deny access to traffic based on rules the network administrator defines. It also shields your computer from direct access to the Internet, hiding them from hackers looking for an easy target. Network Protection Layer 2 – Door Locks: Door locks are represented by the network configuration determining what’s shared and who’s granted access to it. Your usernames should have strong passwords that are hard to crack. Each user should be granted access only to what they need. Network Protection Layer 3 – Alarm Systems: The alarm system includes software-based firewalls and antivirus and antimalware software on the individual computers on the network. If an intruder somehow breaches your network, software will detect unauthorized actions and prevent them. Network Protection Layer 4 – Guard Dogs: The network administrator (you??) needs to be diligent in keeping the systems on the network up to date and secure. It’s critical that software on PCs is kept up to date. Unpatched systems are easy targets for hackers and can allow them access into your network. Networking Ethics Piggybacking means using an open wireless network connection to access the Internet without permission. Wardriving is the practice of driving around and locating wireless access points. List the criteria for a strong password. Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Printed in the United States of America. Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall Visualizing Technology Copyright © 2014 Pearson Education, Inc. Publishing as Prentice Hall