Intro to MIS – MGS351 Network BasicsChapter OverviewTelecommunicationsBasic Components of CommunicationsPowerPoint PresentationSlide 6Characteristics of ChannelsTransmission SignalsTelecommunication ProtocolsSlide 10Telecommunications MediaSlide 12Slide 13Unbound Media – Medium DistanceUnbound Media – Long DistanceComputer NetworksNetworking ComponentsSlide 18Slide 19Slide 20Slide 21Wireless Security Issues802.11 IEEE WLAN Standards2011 wigle.net dataTop SSID NamesHome and Business NetworksPeer-to-Peer NetworkClient/Server NetworkNetwork ClassificationsBus TopologySlide 31Ring TopologySlide 33Star TopologySlide 35Packet SwitchingIntro to MIS – MGS351Network BasicsExtended Learning Module EChapter OverviewTelecommunications–Channels, Protocols and MediaComputer NetworksNetworking ComponentsNetwork ClassificationsNetwork TopologiesTelecommunicationsThe transmission of different forms of data (such as text, audio, video, images, graphics) from one set of electronic devices over media to another set of geographically separated electronic devices.Basic Components of CommunicationsSender: Person or device sending the messageReceiver: Person or device receiving the messageMedium: What carries the message from sender to receiverSender PersonReceiver PersonChannel/Medium A short distance of airMessage VoiceFace-to-face CommunicationSender Telephone, Computer, Video ConferencingChannel/Medium Various Types of Electronic MediaMessage Voice, Data Video, etc.Receiver Telephone, Computer, Video ConferencingTelecommunicationsCharacteristics of ChannelsCharacteristicsDescriptionTransmission rateRate at which channel carries data from one computer to another (bps, kbps, Mbps, Gbps)Volume or capacity of data that a channel can carry.Ways by which data are transmitted. Two ways include asynchronous (one byte at a time) and synchronous (blocks of bytes).Three directions for transmitting data include simplex, half duplex, and full duplex.Information travels as analog or digital signals.BandwidthTransmission modeTransmission directionTransmission signalsTransmission SignalsTelecommunication ProtocolsRules and formats that ensure efficient and error-free electronic communications between computers.TCP/IP, IPv6, 802.11g, 802.11bVary on reliability, speed and ease of useTelecommunication ProtocolsA set of characters that mean the same thing to both the sender and the receiverA set of rules for timing and sequencing messagesA set of methods for detecting and correcting errorsTelecommunications MediaCommunications media - the paths, or physical channels, in a network over which information travels.Wired communications media - transmit information over a closed, connected path. Wireless communications media - transmit information through the air.Telecommunications MediaBounded (wired)twisted-pair (telephone, Ethernet)coaxial cable (cable TV)fiber-optic cable (DWDM)Unbounded (wireless)microwave radio (Bluetooth, WiFi)communication satellitesinfraredhigh-frequency radiosTelecommunications MediaUnbound Media – Medium DistanceRepeater - a device that receives a radio signal, strengthens it and sends it on.Unbound Media – Long DistanceCommunications satellites - microwave repeaters in space.Computer NetworksTwo or more computers connected so that they can communicate with each other and share information, software, peripheral devices, and/or processing power.1. Each computer must have a network card. 2. A network has at least one connecting device.3. There must be communications media connecting the network hardware devices. 4. Each computer must have software that supports the movement of information.Networking Components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.Ethernet card - the most common type of network interface card.Networking ComponentsNetworking ComponentsNetwork hub - a device that connects multiple computers into a network. Switch - a device that connects multiple computers into a network in which multiple communications links can be in operation simultaneously.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.Networking ComponentsNetworking ComponentsFirewall - software and/or hardware that protects a computer or network from intruders. Cat 5, Cat 5e or Cat 6 cable - a better-constructed version of the phone twisted-pair cable.Wireless network access point or wireless access point - a device that allows computers to access a wired network using radio waves. (WiFi, Wireless Fidelity, IEEE 802.11b, 802.11a, 802.11g, 802.11n, or Bluetooth)Wireless Security IssuesYour wireless signal reaches beyond your wallsMany wireless networks are vulnerable to eavesdropping (sniffing)Not all security methods are robustUnauthorized internal access pointsLaptops may automatically connect to networks they previously connected toRogue (evil twin) access points nearby802.11 IEEE WLAN StandardsFrequency Speed Distance802.11a 5 GHz 54 Mbps 115 f802.11b 2.4 GHz 11 Mbps 115 f802.11g 2.4 GHz 54 Mbps 125 f802.11n 2.4/5 GHz 600 Mbps 230 f802.11i WiFi Protected Access (WPA2) to replace WEP802.1x Port based Network Access Control standard2011 wigle.net dataNetworks with crypto: 17,127,424 (52.0%)Networks without crypto: 8,481,146 (25.7%)Networks with default SSID: 3,220,963 (9.7%)Top SSID NamesSSID Percent<no ssid> 6.466%linksys 6.326%NETGEAR 2.093%Default 1.816%Belkin54g 0.846%no_ssid 0.736%hpsetup 0.722%Wireless 0.690%DLINK 0.624%WLAN 0.367%home 0.329%Peer-to-peer network – most often a home network where a small number of computers share hardware, software and/or information.Client/Server Network – this configuration is most commonly used in businesses. One or more computers are servers which provide various services to the other networked computers which are called clients.Home and Business NetworksPeer-to-Peer NetworkClient/Server NetworkNetwork Classifications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. Municipal area network (MAN) - covers a metropolitan area.Wide area network (WAN) – covers a large geographic distances, such