Chapter 5 Local Area Networks Computer Concepts 2013 5 Chapter - - PDF document

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Computer Concepts 2013 Chapter 5

Local Area Networks

5 Chapter Contents

Ø Section A: Network Building Blocks Ø Section B: Wired and Wireless Technologies Ø Section C: Network Setup Ø Section D: Sharing Files Ø Section E: Wireless Security

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5 Section A: Network Building

Blocks

Ø Network Classifications Ø LAN Advantages and Disadvantages Ø Network Devices Ø Network Links Ø Communications Protocols

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5 Network Classifications

Ø Personal Area Network (PAN) – interconnection of personal digital devices or consumer electronics Ø Local Area Network (LAN) – usually connects computers in a single building Ø Metropolitan Area Network (MAN) – public high- speed network with range of about 50 miles Ø Wide Area Network (WAN) – covers a large geographical area and typically consists of several smaller networks

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5 LAN Advantages and

Disadvantages

Ø LANs enable people to work together Ø Sharing networked software can reduce costs Ø Sharing data on a LAN can increase productivity Ø Sharing networked hardware can reduce costs Ø Sharing networked hardware can provide access to a wide range of services and specialized peripheral devices

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5 LAN Advantages and

Disadvantages

Ø One disadvantage of LANs is that when a network malfunctions, all the resources you’re accustomed to accessing are unavailable until the network is repaired Ø LANs are vulnerable to unauthorized access Ø LANs are more vulnerable to malicious code

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5 Network Devices

Ø Each connection point on a network is a node Ø To connect to a LAN, a computer requires network circuitry, sometimes referred to as a network interface card (NIC) Ø A networked peripheral, or network-enabled peripheral, is any device that contains network circuitry to directly connect to a network Ø A network device, or network appliance, is any electronic device that broadcasts network data, boosts signals, or routes data to its destination

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5 Network Devices

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5 Network Links

Ø A communications channel, or link, is a physical path or frequency for signal transmissions Ø Bandwidth is the transmission capacity of a communications channel

Ø Broadband Ø Narrowband

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5 Communications Protocols

Ø Rules for efficiently transmitting data from one network node to another:

Ø Divide messages into packets Ø Affix addresses to packets Ø Initiate transmission Ø Regulate flow of data Ø Check for transmission errors Ø Acknowledge receipt of transmitted data

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5 Communications Protocols

Ø A packet is a “parcel” of data that is sent across a computer network

Ø Circuit-switching technology vs. packet switching technology

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5 Communications Protocols

Ø Every packet that travels over a network includes the address of its destination device Ø A MAC address is a unique number assigned to a network interface card when it is manufactured Ø An IP address is a series of numbers used to identify a network device Ø IP addresses can also be obtained through DHCP

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5 Section B: Wired and Wireless

Technologies

Ø Wired Basics Ø Ethernet Ø Wireless Basics Ø Bluetooth Ø Wi-Fi

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5 Wired Basics

Ø A wired network uses cables to connect network devices Ø Wired networks are fast, secure, and simple to configure Ø Devices tethered to cables have limited mobility

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5 Ethernet

Ø Ethernet is a wired network technology that is defined by IEEE 802.3 standards Ø Simultaneously broadcasts data packets to all network devices

Ø IEEE 802.3 Ø CSMA/CD protocol

Ø Vary in speed from 10Mbps to 100Gbps

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5 Ethernet

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5 Wireless Basics

Ø A wireless network transports data from one device to another without cables or wires

Ø RF signals

Ø Transceiver

Ø Microwaves Ø Infrared light

Ø Slower than wired networks Ø Security concerns

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5 Bluetooth

Ø Bluetooth is a short-range, wireless network technology designed to make its own connections between two devices

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5 Wi-Fi

Ø Wi-Fi refers to a set of wireless networking technologies defined by IEEE 802.11 standards

Ø Wireless ad-hoc protocol Ø Wireless infrastructure protocol

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5 Wi-Fi

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5 Wi-Fi

Ø If your computer is not pre-equipped with wireless circuitry, you can purchase and install a Wi-Fi adapter

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5 Section C: Network Setup

Ø Setup Overview Ø Router Installation Ø Router Configuration Ø Internet Connection Ø Device Connection

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5 Setup Overview

Ø Plug in the router Ø Connect the router to a computer Ø Configure the router Ø Access the router setup utility Ø Create a new router password

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5 Setup Overview

Ø Enter an SSID for the network Ø Activate WEP, WPA, or PSK and create an encryption key Ø Connect an Internet access device Ø Set up the wireless workstations

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5 Router Installation

Ø Look for a Wireless-N router that includes a Gigabit Ethernet switch

Ø Wired and wireless connections

Ø Make sure the number of Ethernet ports is sufficient for the number of wired devices that you intend to connect

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5 Router Installation

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5 Router Configuration

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Ø Before using your network, you should adjust the router’s configuration settings to make sure your network is secure

Ø Stored in router’s EEPROM Ø You must connect a computer to the router Ø You can use your computer’s browser to access the router configuration utility

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5 Router Configuration

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5 Router Configuration

Ø An SSID (service set identifier) is the name of a wireless network Ø Use the router configuration software to change the default SSID

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5 Router Configuration

Ø Each workstation requires a unique address for sending and receiving data

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5 Router Configuration

Ø Wireless encryption scrambles the data transmitted between wireless devices and then unscrambles the data only on devices that have a valid encryption key

Ø WEP Ø WPA Ø PSK

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5 Internet Connection

Ø Your Internet service provider supplies a device called a modem that is designed to carry data to and from the Internet

Ø This device typically has a standard Ethernet port that can be connected to a router Ø Most routers supply a WAN port designed for an Internet connection Ø Plug a standard network cable into the router’s WAN port and connect the other end of the cable into the Internet modem

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5 Internet Connection

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5 Device Connection

Ø Simply turn on any Windows computer with wireless capability and make sure that it is in range of your router

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5 Device Connection

Ø Macs automatically sense available networks and give you the option of connecting to them

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5 Device Connection

Ø Any device that has Wi-Fi capability should be able to connect to your network

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5 Device Connection

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5 Section D: Sharing Files

Ø File Sharing Basics Ø Accessing Shared Files Ø Sharing Your Files Ø File Servers Ø Network Troubleshooting

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5 File Sharing Basics

Ø File sharing allows files containing documents, photos, music, and other data to be accessed from computers other than the one on which they are stored Ø Once your network gives you access to other computers on the network, you can view a list of files stored there

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5 Accessing Shared Files

Ø To see a list of devices on your network, you can use your operating system’s file management utility Ø Network discovery is a setting that affects whether your computer can see other computers on a network, and whether your computer can be seen by others

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5 Accessing Shared Files

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5 Sharing Your Files

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5 Sharing Your Files

Ø When you activate file sharing, files in Public folders can be accessed by other network users Ø You also can make specific files shareable Ø If you want the convenience of sharing files, limit what you share and who you share it with:

Ø Assign permissions to files Ø Limit sharing to specific people Ø Remove sharing from files you no longer want to share Ø Use a homegroup if your network is composed of Windows computers Ø A homegroup is a collection of trusted Windows computers that automatically share files and folders

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5 Sharing Your Files

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5 File Servers

Ø A file server is a computer whose primary purpose is to be a repository for files that can be accessed by network workstations

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5 Troubleshooting

Ø Network problems can stem from a variety of sources

Ø Cables Ø Signal strength Ø Security Ø Interference Ø Network devices Ø Settings Ø Switches

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