Internet and LAN Technology

2 Chapter Contents Section A: Network Building BlocksNetwork Building Blocks Section B: Local Area NetworksLocal Area Networks Section C: Internet TechnologyInternet Technology Section D: Internet AccessInternet Access

3 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

4 Section A: Network Building Blocks Network Links Analog and Digital Signals Bandwidth Communications Protocols

5 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

6 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

7 Network Classifications

8 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

9 Organizational Structure: Client/Server and Peer-to-Peer

10 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

11 Physical Topology

12 Physical Topology

13 Network Links Wired network –Twisted-pair cable –Coaxial cable –Fiber-optic cable Wireless network –RF signals –Microwaves –Infrared light

14 Analog and Digital Signals

15 Bandwidth The transmission capacity of a communications channel –High-bandwidth channel (broadband) Cable TV DSL –Low-bandwidth channel (narrowband) Telephone system

16 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

17 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)

18 Section B: Local Area Networks LAN Standards Ethernet Wi-Fi HomePNA and HomePLC Networks Installing a LAN Using a LAN

19 LAN Standards LAN Technologies are standardized by the IEEE –ARCnet –Token Ring technology –FDDI –Ethernet –Wi-Fi

20 Ethernet Simultaneously broadcasts data packets to all network devices –IEEE –CSMA/CD protocol

21 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

22 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

23 Wi-Fi Wireless networking technologies that are compatible with Ethernet

24 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

25 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

26 Installing a LAN CLICK TO START

27 Using a LAN In this drive mapping example, a servers drive C is mapped as drive F by a workstation. After the mapping is complete, the servers hard disk appears in the workstations directory as drive F and can be used just as though it were a drive connected directly to the workstation. CLICK TO START

28 Using a LAN You can allow other network users to view and edit files in the folders youve designated as shared

29 Using a LAN The Network Connection tool helps you troubleshoot connection problems

30 Section C: Internet Technology Background Internet Structure ISP Infrastructure Internet Protocols IP Addresses Domain Names

31 Background The Advanced Research Projects Agency designed ARPANET The Internet has an estimated 200 million nodes and 500 million users today

32 Internet Structure

33 Internet Structure Ping is used to find out whether a site is up and running The Traceroute utility records a packets path

34 ISP Infrastructure

35 Internet Protocols TCP and IP serve as the primary protocols responsible for message transmission on the Internet

36 IP Addresses IP addresses are addresses that identify computers on the Internet –Static IP address –Dynamic IP address

37 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 Internets Domain Name System

38 Domain Names

39 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 youve found an available domain name you like, you can continue the registration process by filling out a simple online form. CLICK TO START

40 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

41 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

42 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

43 Cable Internet Service

44 Cable Internet Service Cable modems convert your computers signal into one that can travel over the CATV network Always-on connection Neighborhood network

45 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

46 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

47 Wireless Internet Service Direct satellite service (DSS)

48 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

49 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

50 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

51 Mobile Internet Access Handheld device services include: –Short message service (SMS) –Multimedia messaging (MMS) –Music fingerprinting –Games –City guides – –News, sports, stocks, and weather

52 Mobile Internet Access Cellular service options

53 Internet Connection Roundup

C HAPTER 5 C OMPLETE Internet and LAN Technology