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Internet and LAN Technology. Chapter Contents. Section A: Network Building Blocks Section B: Local Area Networks Section C: Internet Technology Section D: Internet Access. Section A: Network Building Blocks. Network Advantages and Challenges Network Classifications
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Chapter Contents • Section A: Network Building Blocks • Section B: Local Area Networks • Section C: Internet Technology • Section D: Internet Access
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
Section A: Network Building Blocks • Network Links • Analog and Digital Signals • Bandwidth • Communications Protocols
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
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
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 high-speed network with range of about 50 miles • Wide Area Network (WAN) – consists of several smaller networks
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
Network Links • Wired network • Twisted-pair cable • Coaxial cable • Fiber-optic cable • Wireless network • RF signals • Microwaves • Infrared light
Bandwidth • The transmission capacity of a communications channel • High-bandwidth channel (broadband) • Cable TV • DSL • Low-bandwidth channel (narrowband) • Telephone system
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
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)
Section B: Local Area Networks • LAN Standards • Ethernet • Wi-Fi • HomePNA and HomePLC Networks • Installing a LAN • Using a LAN
LAN Standards • LAN Technologies are standardized by the IEEE • ARCnet • Token Ring technology • FDDI • Ethernet • Wi-Fi
Ethernet • Simultaneously broadcasts data packets to all network devices • IEEE 802.3 • CSMA/CD protocol
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
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
Wi-Fi • Wireless networking technologies that are compatible with Ethernet
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
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
Installing a LAN CLICK TO START
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
Using a LAN • You can allow other network users to view and edit files in the folders you’ve designated as shared
Using a LAN • The Network Connection tool helps you troubleshoot connection problems
Section C: Internet Technology • Background • Internet Structure • ISP Infrastructure • Internet Protocols • IP Addresses • Domain Names
Background • The Advanced Research Projects Agency designed ARPANET • The Internet has an estimated 200 million nodes and 500 million users today
Internet Structure • Ping is used to find out whether a site is up and running • The Traceroute utility records a packet’s path
Internet Protocols • TCP and IP serve as the primary protocols responsible for message transmission on the Internet
IP Addresses • IP addresses are addresses that identify computers on the Internet • Static IP address • Dynamic IP address
Domain Names • Easy-to-remember names for Internet servers • Ends with an extension that indicates its top-level domain • Every domain name corresponds to a unique IP address • Domain Name System • ICANN coordinates technical management of the Internet’s Domain Name System
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
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
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
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
Cable Internet Service • Cable modems convert your computer’s signal into one that can travel over the CATV network • Always-on connection • Neighborhood network
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
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, high-capacity data transmission
Wireless Internet Service • Direct satellite service (DSS)
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
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
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