Computer Concepts 2012 Chapter 6 The Internet

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

6 True Questions  TCP, Transmission Control Protocol,  IP, internet protocol –UDP, HTTP, and FTP are examples of protocols used on the Internet. – is an example of an IP address. –.edu and.ca are examples of top-level domains. –Internet-based servers can handle multiple tasks using different ports. Chapter 6: The Internet3

6 TCP/IP Model Chapter 6: The Internet4 Data UDP headerData IP headerIP data Frame Header

6 True Questions  Utilities such as Ping and Traceroute help you gauge the speed of your Internet connection.  10 Mbps is a broadband Internet connection.  Dial-up, ISDN, and DSL [digital subscriber line] provide Internet access using telephone cabling.  Cable Internet service is fast because it has little latency.  WiMAX uses low-earth orbiting satellites to transport data to the Internet. Chapter 6: The Internet5

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6 True Questions  Portable Internet access includes portable WiMAX and Wi-Fi.  UTMS, Universal Mobile Telecommunications System –EDGE, and –HSUPA are examples of ????.  VoIP uses packet-switched technology to send digital data  digitization of the analog voice signal, encoding, packetization, and transmission as Internet Protocol (IP) packets over a packet-switched network. Chapter 6: The Internet7

6 SECTION A Chapter 6: The Internet8 Internet Technology  Background  Internet Infrastructure  Internet Protocols, Addresses, and Domains  Connection Speed

6 Question  One reason the Internet works is because TCP/IP offers a global addressing standard.  Which one of the following is accurate in the context of Internet addresses? –C. A domain name, such as amazon.com corresponds to a unique IP address. Chapter 6: The Internet9

6 10 Background  The ARPANET, created in 1969, connected computers at UCLA, Stanford Research Institute, Univ of Utah, and Univ of Calif 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 500 million nodes and more than 2 billion users, the Internet is huge

6 Chapter 6: The Internet11 Internet Infrastructure  The Internet is not owned or operated by any single corporation or government  Internet backbone: a network of high-capacity communication links providing the main routes for data traffic across the Internet  Backbone links and routers are maintained by NSPs –network service providers (NSPs)  NSP equipment and links are tied together by NAPs –network access points (NAPs)  Internet service provider (ISP): a company provides Internet access to individuals, businesses, and smaller ISPs

6 Internet Infrastructure Chapter 6: The Internet12

6 ISP Equipment Chapter 6: The Internet13

6 Chapter 6: The Internet14 Internet Infrastructure  To communicate with an ISP, your computer uses some type of communications device, such as a modem

6 Internet Protocols, Addresses, and Domains  A computer can have a permanently assigned static IP address or a temporarily assigned dynamic IP address Chapter 6: The Internet15

6 Internet Protocols, Addresses, & Domains Chapter 6: The Internet16

6 Internet Protocols, Addresses, & Domains Chapter 6: The Internet17

6 Chapter 6: The Internet18 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 measured in “ms”, miliseconds,.001 second  3 milliseconds — a housefly's wing flaphousefly  5 milliseconds — a honey bee's wing flap

6 Chapter 6: The Internet19  This time is referred to as latency –Ping –Traceroute  Upstream vs. downstream speed

6 Chapter 6: The Internet20 Connection Speed  asymmetric Internet connection: –upstream speeds differ from downstream speeds  symmetric Internet connection: –upstream and downstream speeds are the same  Internet connection options –Fixed Internet access –Portable Internet access –Mobile Internet access

6 SECTION B Chapter 6: The Internet21 Fixed Internet Access  Dial-up Connections  DSL, ISDN, and Dedicated Lines  Cable Internet Service  Satellite Internet Service  Fixed Wireless Service  Fixed Internet Connection Roundup

6 Question  Although ISPs offer Internet access though dial-up, satellites, WiMAX, ISDN, and DSL, cable Internet is currently the preferred access method. Why? –B. It is the fastest and most widely available technology. Chapter 6: The Internet22

6 Chapter 6: The Internet23 Dial-up Connections  Dial-up connection is a fixed Internet connection –It uses a voiceband modem and –telephone lines to transport data –between your computer and your ISP

6 Chapter 6: The Internet24 Dial-up Connections  Voiceband modem converts signals from your computer into audible analog signals that travel over telephone lines  Modem speed is measured in bits per second

6 Chapter 6: The Internet25 Dedicated Lines,DSL, and ISDN  T1, T3, and T4 lines are leased from the telephone company and offer fast, high-capacity data transmission  DSL is a high-speed, digital, always-on Internet access technology that runs over standard phone lines DSL modem

6 Chapter 6: The Internet26 Cable Internet Service  Cable Internet service distributes always-on, broadband Internet access over the same infrastructure that offers cable television service

6 Chapter 6: The Internet27 Cable Internet Service  Cable modems convert your computer’s signal into one that can travel over the CATV network  Always-on connection  DOCSIS-compliant cable modems

6 Chapter 6: The Internet28 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

6 Symmetric vs Asymmetric  Asymmetric is greater toward the customer premises (known as downstream) than the reverse (known as upstream).downstreamupstream Chapter 6: The Internet29

6 Satellite Internet Service Chapter 6: The Internet30

6 Chapter 6: The Internet31 Fixed Wireless Service  Fixed wireless Internet service broadcasts signals in order to offer Internet access to large areas –WiMAX –A WiMAX system transmits data to and from WiMAX antennas mounted on towers –Under ideal conditions, WiMAX can transmit data at 70 Mbps

6 Fixed Internet Connection Roundup Chapter 6: The Internet32

6 SECTION C Chapter 6: The Internet33 Portable and Mobile Internet Access  Internet to Go  Wi-Fi Hotspots  Portable and Mobile WiMAX  Portable Satellite Service  Cellular Data Service

6 Question  What is the difference between portable Internet access and mobile Internet access? –A. With portable access you cannot work online while moving very far.. Chapter 6: The Internet34

6 Chapter 6: The Internet35 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

6 Chapter 6: The Internet36 Wi-Fi Hotspots  A Wi-Fi hotspot is an area in which the public can access a Wi-Fi network that offers Internet service

6 Chapter 6: The Internet37 Portable and Mobile WiMAX  WiMAX can be both portable and mobile.  Mobile WiMAX

6 SECTION D Chapter 6: The Internet38 Internet Services  Real-Time Messaging  Voice over IP  Cloud Computing  Grid Computing  FTP  File Sharing Networks

6 SECTION D Do Not TEXT and DRIVE ! Chapter 6: The Internet39

6 Chapter 6: The Internet40 Real-Time Messaging  A networked-based, real-time messaging system allows people to exchange short messages while they are online –Instant messaging (IM) –Chat

6 Chapter 6: The Internet41 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

6 Wikis, Blogs, and Tweets  A wiki allows participants to modify material  A blog (short for Web log) is similar to an online diary; it is maintained by one person and contains a series of entries on one or more topics  A tweet is a short message of 140 characters or less, posted to the Twitter Web site Chapter 6: The Internet42

6 Wikis, Blogs, and Tweets Chapter 6: The Internet43

6 Cloud Computing  The concept of cloud computing depends on a grid of servers and storage devices that offer Internet-accessible computing services ranging from hardware to office productivity applications and complex corporate data processing –Google Apps –Amazon’s Elastic Compute Cloud Chapter 6: The Internet44

6 Cloud Computing Chapter 6: The Internet45

6 Chapter 6: The Internet46 Grid Computing  A grid computing system is a network of computers harnessed together to perform processing tasks project

6 FTP Chapter 6: The Internet47

6 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 Chapter 6: The Internet48

6 SECTION E Chapter 6: The Internet49 Internet Security  Intrusion Attempts  Securing Ports  Routers and NAT  Virtual Private Networks

6 Chapter 6: The Internet50 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

6 Chapter 6: The Internet51 Intrusion Attempts

6 Securing Ports  One of the easiest steps to enhance your computer’s security is to turn it off when you aren’t using it  A firewall is software or hardware designed to filter out suspicious packets attempting to enter or leave a computer Chapter 6: The Internet52

6 Chapter 6: The Internet53 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 that 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

6 Routers and NAT Chapter 6: The Internet54

6 Chapter 6: The Internet55 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

6 Chapter 6: The Internet56 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

6 Chapter 6: The Internet57 Virtual Private Networks

Computer Concepts 2012 Chapter 6 Complete