Internet and LAN Technology Chapter Contents • • • • Section A: Network Building Blocks Section B: Local Area Networks Section C: Internet Technology Section D: Internet Access 2 Section A: Network Building Blocks • Network Advantages and Challenges • Network Classifications • Geographic Scope: PANs, NANs, LANs, MANs, and WANs • Organizational Structure: Client/Server and Peer-to-Peer • Physical Topology 3 Section A: Network Building Blocks • • • • Network Links Analog and Digital Signals Bandwidth Communications Protocols 4 Network Advantages and Challenges • Sharing networked hardware can reduce costs • Sharing networked hardware can provide access to a wide range of services and specialized peripheral devices • Sharing networked software can reduce costs • Sharing data on a network is easy • Networks enable people to work together regardless of time and place 5 Network Advantages and Challenges • Networks may be vulnerable to unauthorized access from many sources and locations – More vulnerable than standalone computers • Wireless networks can be tapped from a “snooping” computer • Networked computers are susceptible to an increasing number of worms, Trojan horses, and blended threats 6 Network Classifications 7 Geographical Scope: PANs, NANs, LANs, MANs, and WANs • Personal Area Network (PAN) – interconnection of personal digital devices • Neighborhood Area Network (NAN) – connectivity spread over several buildings • Local Area Network (LAN) – usually connects computers in a single building • Metropolitan Area Network (MAN) – public highspeed network with range of about 50 miles • Wide Area Network (WAN) – consists of several smaller networks 8 Organizational Structure: Client/Server and Peer-to-Peer 9 Physical Topology • Arrangement of devices in a network • Each connection point on a network is referred to as a node • A bridge can connect two similar networks • A gateway joins two dissimilar networks – Router 10 Physical Topology 11 Physical Topology 12 Network Links • Wired network – Twisted-pair cable – Coaxial cable – Fiber-optic cable • Wireless network – RF signals – Microwaves – Infrared light 13 Analog and Digital Signals 14 Bandwidth • The transmission capacity of a communications channel – High-bandwidth channel (broadband) • Cable TV • DSL – Low-bandwidth channel (narrowband) • Telephone system 15 Communications Protocols • Rules for efficiently transmitting data from one network node to another – Dividing messages into packets – Affixing addresses to packets – Initiating transmission – Regulating the flow of data – Checking for transmission errors – Acknowledging receipt of transmitted data 16 Communications Protocols • A packet is a “parcel” of data that is sent across a computer network – Circuit-switching technology vs. packet switching technology • Voice over IP (VoIP) 17 Section B: Local Area Networks • • • • • • LAN Standards Ethernet Wi-Fi HomePNA and HomePLC Networks Installing a LAN Using a LAN 18 LAN Standards • LAN Technologies are standardized by the IEEE – ARCnet – Token Ring technology – FDDI – Ethernet – Wi-Fi 19 Ethernet • Simultaneously broadcasts data packets to all network devices – IEEE 802.3 – CSMA/CD protocol 20 Ethernet On an Ethernet, data travels on a “first come, first served” basis. If two workstations attempt to send data at the same time, a collision occurs. That data must be resent. CLICK TO START 21 Ethernet • Varies in speed from 10 Mbps to 10 Gbps • An Ethernet card is designed to support the Ethernet protocols • Ethernet hubs link workstations via cables – Uplink port 22 Wi-Fi • Wireless networking technologies that are compatible with Ethernet 23 Wi-Fi • WEP (Wired Equivalent Privacy) encrypts data traveling over wireless networks • Equipment required for a wireless network – Wi-Fi card – Wireless access point • Bluetooth is a short-range wireless network technology 24 HomePNA and HomePLC Networks • HomePNA networks utilize existing telephone wiring to connect network devices – Special NICs and cables are required • HomePLC networks transmit data over power lines as low-frequency radio waves 25 Installing a LAN CLICK TO START 26 Using a LAN In this drive mapping example, a server’s drive C is mapped as drive F by a workstation. After the mapping is complete, the server’s hard disk appears in the workstation’s directory as drive F and can be used just as though it were a drive connected directly to the workstation. CLICK TO START 27 Using a LAN • You can allow other network users to view and edit files in the folders you’ve designated as shared 28 Using a LAN • The Network Connection tool helps you troubleshoot connection problems 29 Section C: Internet Technology • • • • • • Background Internet Structure ISP Infrastructure Internet Protocols IP Addresses Domain Names 30 Background • The Advanced Research Projects Agency designed ARPANET • The Internet has an estimated 200 million nodes and 500 million users today 31 Internet Structure 32 Internet Structure • Ping is used to find out whether a site is up and running • The Traceroute utility records a packet’s path 33 ISP Infrastructure 34 Internet Protocols • TCP and IP serve as the primary protocols responsible for message transmission on the Internet 35 IP Addresses • IP addresses are addresses that identify computers on the Internet – Static IP address – Dynamic IP address 36 Domain Names • Easy-to-remember names for Internet servers – Ends with an extension that indicates its toplevel domain • Every domain name corresponds to a unique IP address – Domain Name System • ICANN coordinates technical management of the Internet’s Domain Name System 37 Domain Names 38 Domain Names The first step in registering a domain name is to find out whether the name is currently in use or reserved for future use. If a domain name is not available, consider using a different top-level domain, such as biz instead of com. After you’ve found an available domain name you like, you can continue the registration process by filling out a simple online form. CLICK TO START 39 Section D: Internet Access • • • • • • • Dial-up Connections Cable Internet Service DSL, ISDN, and Dedicated Lines Wireless Internet Services LAN Internet Access Mobile Internet Access Internet Connection Roundup 40 Dial-up Connections • Uses POTS to transport data between your computer and your ISP • A modem converts digital signals from your computer into analog signals that can travel over telephone lines, and vice versa – Modulation / Demodulation 41 Dial-up Connections • Modems are still required, despite digital telephone technology • Modem speed is measured as baud rate • Many Internet connection methods provide faster downstream transmission rates than upstream rates 42 Cable Internet Service 43 Cable Internet Service • Cable modems convert your computer’s signal into one that can travel over the CATV network • Always-on connection • Neighborhood network 44 DSL, ISDN, and Dedicated Lines • DSL is a high-speed, digital, always-on Internet access technology that runs over standard telephone lines – DSLAM – Most DSL installations require service technicians • DSL modem 45 DSL, ISDN, and Dedicated Lines • ISDN connections are slower than DSL and cable Internet service, but faster than dial-up – ISDN terminal adapter connects a computer to a telephone wall jack and converts signals to travel over ISDN connection • T1, T3, and T4 lines are leased from the telephone company, and offer fast, highcapacity data transmission 46 Wireless Internet Service • Direct satellite service (DSS) 47 Wireless Internet Service • Fixed wireless Internet service broadcasts RF signals in order to offer Internet access to large areas – WiMAX – Wireless service providers are usually local or regional businesses 48 LAN Internet Access • Cost-effective way to share one Internet connection among several computers • To establish LAN Internet access, you need: – An operational wired or wireless LAN – A router or a hub with router capabilities – A high-speed Internet connection, such as DSL, ISDN, or cable Internet – A modem that corresponds to your Internet connection type 49 Mobile Internet Access • A Wi-Fi hotspot is a wireless broadband Internet service offered in a public location – WISP • WAP is a communications protocol that provides Internet access from handheld devices 50 Mobile Internet Access • Handheld device services include: – Short message service (SMS) – Multimedia messaging (MMS) – Music fingerprinting – Games – City guides – E-mail – News, sports, stocks, and weather 51 Mobile Internet Access • Cellular service options 52 Internet Connection Roundup 53 CHAPTER 5 COMPLETE Internet and LAN Technology