1. The Internet Chapter 6

2. 6 Chapter 6: The Internet2 Chapter Contents Section A: Internet Technology Section B: Fixed Internet Access Section C: Portable and Mobile Internet Access Section D: Internet Services Section E: Internet Security

3. 6 SECTION A Chapter 6: The Internet3 Internet Technology Background Internet Infrastructure Internet Protocols, Addresses, and Domains Connection Speed

4. 6 Chapter 6: The Internet4 Background The ARPANET, created in 1969, connected computers at UCLA, Stanford Research Institute, University of Utah, and University of California at Santa Barbara Today, the Internet connects computers all over the globe and supplies information to people of all ages and interests With an estimated 200 million nodes and 1 billion users, the Internet is huge

5. 6 Chapter 6: The Internet5 Internet Infrastructure The Internet is not owned or operated by any single corporation or government The Internet backbone is a network of high-capacity communications links that provides the main routes for data traffic across the Internet Backbone links and routers are maintained by network service providers (NSPs) NSP equipment and links are tied together by network access points (NAPs) An Internet service provider (ISP) is a company that offers Internet access to individuals, businesses, and smaller ISPs

6. 6 Chapter 6: The Internet6 Internet Infrastructure

7. 6 Chapter 6: The Internet7 Internet Infrastructure To communicate with an ISP, your computer uses some type of communications device, such as a modem

8. 6 Chapter 6: The Internet8 Internet Protocols, Addresses, and Domains

9. 6 Chapter 6: The Internet9 Internet Protocols, Addresses, and Domains A domain name is a key component of Web addresses, e-mail addresses, and addresses on the Web called URLs

10. 6 Chapter 6: The Internet10 Internet Protocols, Addresses, and Domains

11. 6 Chapter 6: The Internet11 Internet Protocols, Addresses, and Domains 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 can continue the registration process by filling out a simple online form.

12. 6 Chapter 6: The Internet12 Connection Speed Data travels over the Internet at an incredible speed The elapsed time for data to make a round trip from point A to point B and back to point A is referred to as latency –Ping –Traceroute Upstream vs. downstream speed

13. 6 Chapter 6: The Internet13 Connection Speed When upstream speeds differ from downstream speeds, you have an asymmetric Internet connection When upstream and downstream speeds are the same, you have a symmetric Internet connection Internet connection options –Fixed Internet access –Portable Internet access –Mobile Internet access

14. 6 SECTION B Chapter 6: The Internet14 Fixed Internet Access Dial-up Connections DSL, ISDN, and Dedicated Lines Cable Internet Service Satellite Internet Service Fixed Wireless Service Fixed Internet Connection Roundup

15. 6 Chapter 6: The Internet15 Dial-up Connections A dial-up connection is a fixed Internet connection that uses a voiceband modem and telephone lines to transport data between your computer and your ISP

16. 6 Chapter 6: The Internet16 Dial-up Connections A voiceband modem converts the signals from your computer into signals that can travel over telephone lines Modem speed is measured in bits per second

17. 6 Chapter 6: The Internet17 DSL, ISDN, and Dedicated Lines T1, T3, and T4 lines are leased from the telephone company, and offer fast, high- capacity data transmission ISDN (Integrated Services Digital Network) is a type of fixed Internet connection that moves data at speeds of 64 Kbps or 128 Kbps over ordinary telephone lines –ISDN terminal adapter connects a computer to a telephone wall jack and converts signals to travel over ISDN connection

18. 6 Chapter 6: The Internet18 DSL, ISDN, and Dedicated Lines DSL is a high-speed, digital, always-on Internet access technology that runs over standard phone lines –Most DSL installations require service technicians DSL modem

19. 6 Chapter 6: The Internet19 Cable Internet Service Cable Internet service distributes always-on broadband Internet access over the same infrastructure that offers cable television service

20. 6 Chapter 6: The Internet20 Cable Internet Service Cable modems convert your computers signal into one that can travel over the CATV network Always-on connection DOCSIS-compliant cable modems

21. 6 Chapter 6: The Internet21 Satellite Internet Service Satellite Internet service distributes always- on, high-speed asymmetric Internet access by broadcasting signals to and from a personal satellite dish A satellite modem is a device that modulates data signals from a computer into a frequency band that can be carried to the satellite dish where it is converted to another frequency, amplified, and transmitted

22. 6 Chapter 6: The Internet22 Satellite Internet Service

23. 6 Chapter 6: The Internet23 Fixed Wireless Service Fixed wireless Internet service broadcasts RF signals in order to offer Internet access to large areas –WiMAX –AWiMAX system transmits data to and from WiMAX antennas mounted on towers –Under ideal conditions, WiMAX can transmit data at 70 Mbps

24. 6 Chapter 6: The Internet24 Fixed Internet Connection Roundup

25. 6 SECTION C Chapter 6: The Internet25 Portable and Mobile Internet Access Internet to Go Wi-Fi Hotspots Portable and Mobile WiMAX Portable Satellite Service Cellular Data Service

26. 6 Chapter 6: The Internet26 Internet To Go Portable Internet access can be defined as the ability to easily move your Internet service from one location to another Mobile Internet access offers a continuous Internet connection as you are walking or riding in a bus, car, train, or plane

27. 6 Chapter 6: The Internet27 Wi-Fi Hotspots A Wi-Fi hotspot is an area in which the public can access a Wi-Fi network that offers Internet service Wi-Fi does not typically provide acceptable mobile Internet access because you can only remain connected within range of the networks hotspot

28. 6 Chapter 6: The Internet28 Portable and Mobile WiMAX WiMAX can be used as a portable technology because Internet access is available to subscribers anywhere within a towers coverage area You use the same Internet service provider whether you are at home or on the road. Mobile WiMAX

29. 6 Chapter 6: The Internet29 Portable Satellite Service

30. 6 Chapter 6: The Internet30 Cellular Data Services Using cellular phone technology to access the Internet offers mobility that is not yet possible with most of todays wired or wireless computer network technologies

31. 6 Chapter 6: The Internet31 Cellular Data Services The fastest cellular technologies for Internet access are EDGE, EV-DO, and HSUPA Most cellular service providers offer a data service plan for accessing the Internet You can use a cellular-ready PDA, such as Palm Treo, Blackberry, HP iPAQ, or Dell Axim to directly access the Internet

32. 6 SECTION D Chapter 6: The Internet32 Internet Services Real-Time Messaging Voice over IP Grid Computing FTP File sharing

33. 6 Chapter 6: The Internet33 Real-Time Messaging A networked-based real-time messaging system allows people to exchange short messages while they are online –Instant messaging (IM) –Chat

34. 6 Chapter 6: The Internet34 Voice over IP VoIP (Voice over Internet Protocol) or Voice over IP, is a technology in which a broadband Internet connection is used to place telephone calls instead of the regular phone system To set up a standard VoIP system, you can use an inexpensive ATA, IP phone, wireless IP phone, or USB phone

35. 6 Chapter 6: The Internet35 Voice over IP Advantages –Low cost –Flexibility –Phone number moves with you Disadvantages –Quality can vary –Must have power to work

36. 6 Chapter 6: The Internet36 Grid Computing A grid computing system is a network of diverse computers, such as PCs, Macs, workstations, and servers, in which each computer contributes processing resources to solve a single problem SETI@home

37. 6 Chapter 6: The Internet37 FTP

38. 6 Chapter 6: The Internet38 FTP

39. 6 Chapter 6: The Internet39 File Sharing P2P file sharing uses peer- to-peer (P2P) protocols that allow users to obtain files from other users located anywhere on the Internet BitTorrent is a file sharing protocol that distributes the role of file server across a collection of dispersed computers

40. 6 SECTION E Chapter 6: The Internet40 Internet Security Intrusion Attempts Securing Ports Routers and NAT Virtual Private Networks

41. 6 Chapter 6: The Internet41 Intrusion Attempts An intrusion is any access to data or programs by hackers, criminals, or other unauthorized persons Looking for open ports is one of the most common ways of gaining unauthorized access to a network-based computer A port probe (or port scan) uses automated software to locate computers that have open ports and are vulnerable to unauthorized access

42. 6 Chapter 6: The Internet42 Intrusion Attempts

43. 6 Chapter 6: The Internet43 Securing Ports One of the easiest steps to enhance your computers security is to turn it off when you arent using it A firewall is software or hardware designed to filter out suspicious packets attempting to enter or leave a computer

44. 6 Chapter 6: The Internet44 Securing Ports

45. 6 Chapter 6: The Internet45 Routers and NAT Routers are intended to work on LANs to monitor and direct packets being transported from one device to another A routable IP address is one which can be accessed by packets on the Internet A private IP address is a non-routable IP address that can be used within a LAN, but not for Internet data transport

46. 6 Chapter 6: The Internet46 Routers and NAT

47. 6 Chapter 6: The Internet47 Routers and NAT Network address translation (NAT) is the process your router uses to keep track of packets and their corresponding private or public IP addresses

48. 6 Chapter 6: The Internet48 Virtual Private Networks It is possible to secure remote connections by setting up virtual private network (VPN) access to a remote access server in the corporate office Access to a VPN is usually by invitation only. Employees who need to access a VPN are given the necessary instructions, addresses, and passwords to make connections

49. 6 Chapter 6: The Internet49 Virtual Private Networks

50. Chapter 6 Complete The Internet