McGraw-Hill Technology Education

Chapter 7, 8 & 9 Chapter 7Network BasicsData Communications

Chapter 8The Internet and the World Wide WebE-mail and Other Internet Services

Chapter 9Connecting to the InternetDoing Business in the Online World

Chapter 7Network BasicsData Communications

Chapter 8The Internet and the World Wide WebE-mail and Other Internet Services

Chapter 9Connecting to the InternetDoing Business in the Online World

Chapter 9 Objectives

Discuss the components required for Discuss the components required for successful communicationssuccessful communications

Discuss the components required for Discuss the components required for successful communicationssuccessful communications

Identify various sendingIdentify various sendingand receiving devicesand receiving devices

Identify various sendingIdentify various sendingand receiving devicesand receiving devices

Describe uses of computer communicationsDescribe uses of computer communicationsDescribe uses of computer communicationsDescribe uses of computer communications

List advantages of using a networkList advantages of using a networkList advantages of using a networkList advantages of using a network

Differentiate among client/server,Differentiate among client/server,peer-to-peer, and P2P networkspeer-to-peer, and P2P networks

Differentiate among client/server,Differentiate among client/server,peer-to-peer, and P2P networkspeer-to-peer, and P2P networks

Describe the various network Describe the various network communications standardscommunications standards

Describe the various network Describe the various network communications standardscommunications standards

Explain the purpose ofExplain the purpose ofcommunications softwarecommunications software

Explain the purpose ofExplain the purpose ofcommunications softwarecommunications software

Describe various types of lines for Describe various types of lines for communications over the telephone networkcommunications over the telephone network

Describe various types of lines for Describe various types of lines for communications over the telephone networkcommunications over the telephone network

Describe commonly usedDescribe commonly usedcommunications devicescommunications devices

Describe commonly usedDescribe commonly usedcommunications devicescommunications devices

Discuss different ways to set upDiscuss different ways to set upa home networka home network

Discuss different ways to set upDiscuss different ways to set upa home networka home network

Identify various physical and wireless Identify various physical and wireless transmission mediatransmission media

Identify various physical and wireless Identify various physical and wireless transmission mediatransmission media

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Communications Over the Telephone Network

What is the public switched telephone network (PSTN)?

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Worldwide telephone system Worldwide telephone system that handles voice-oriented that handles voice-oriented telephone callstelephone calls

Voice Over IP

Communications Over the Telephone Network

What is a dial-up line?

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Temporary connection using telephone line for Temporary connection using telephone line for communicationscommunications Costs no more than making regular callCosts no more than making regular call Computers at any two locations can establish a connection using Computers at any two locations can establish a connection using

modems and telephone networkmodems and telephone network

Communications Over the Telephone Network

What is a dedicated line?

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Five types are ISDN line, Five types are ISDN line, DSL, FTTP, T-carrier line, DSL, FTTP, T-carrier line, and ATMand ATM

Always-on connection Always-on connection between two between two communications communications devicesdevices

Communications DevicesWhat are examples of communications devices?

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Common types are dial-up modems, ISDN and Common types are dial-up modems, ISDN and DSL modems, cable modems, wireless modems, DSL modems, cable modems, wireless modems,

network cards, wireless access points, network cards, wireless access points, routers, and hubsrouters, and hubs

ISDN and DSL modems send and ISDN and DSL modems send and receive data from ISDN and DSL linesreceive data from ISDN and DSL lines

Communications DevicesWhat is a dial-up modem?

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A dial-up modem converts digital signals to analog signals and vice versaA dial-up modem converts digital signals to analog signals and vice versa Usually in the form of an adapter cardUsually in the form of an adapter card

Communications DevicesWhat are ISDN and DSL modems?

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Communications devices that send and Communications devices that send and receive digital ISDN and DSL signalsreceive digital ISDN and DSL signals

Communications devices that send and Communications devices that send and receive digital ISDN and DSL signalsreceive digital ISDN and DSL signals

Usually external devices in which one Usually external devices in which one end connects to a telephone line and the other end connects to a telephone line and the other

end connects to a port on the system unitend connects to a port on the system unit

Usually external devices in which one Usually external devices in which one end connects to a telephone line and the other end connects to a telephone line and the other

end connects to a port on the system unitend connects to a port on the system unit

Communications DevicesWhat is a cable

modem?

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Sends and receives Sends and receives data over cable data over cable television networktelevision network

Much faster than Much faster than dial-up modem or dial-up modem or ISDNISDN

Sometimes called a Sometimes called a broadband modembroadband modem

Communications DevicesWhat is a wireless modem?

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Allows access to the Allows access to the Web wirelessly from Web wirelessly from a notebook a notebook computer, a smart computer, a smart phone, or other phone, or other mobile devicemobile device

Typically use the Typically use the same waves used by same waves used by cellular telephonescellular telephones

Communications DevicesWhat is a network card?

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Adapter card, PC Adapter card, PC Card, ExpressCard Card, ExpressCard module, USB module, USB network adapter, or network adapter, or flash card that flash card that enables computer or enables computer or device to access device to access networknetwork

Sometimes called Sometimes called network interface network interface card (NIC)card (NIC)

Communications DevicesWhat is a wireless access point?

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Central Central communications communications device that allows device that allows computers and computers and devices to transfer devices to transfer data wirelessly among data wirelessly among themselves or themselves or wirelessly to a wired wirelessly to a wired networknetwork

Communications DevicesWhat is a router?

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Connects computers and Connects computers and transmits data to correct transmits data to correct destination on networkdestination on network

Routers forward data on Routers forward data on Internet using fastest available Internet using fastest available pathpath

Some routers have a built-in Some routers have a built-in hardware firewallhardware firewall

Communications DevicesWhat is a hub or switch?

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Device that provides central Device that provides central point for cables in networkpoint for cables in network

Home NetworksWhat is a home network?

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Multiple computers Multiple computers connected in homeconnected in home

Several types of home Several types of home networksnetworks

Ethernet Ethernet — connect — connect computers via cablecomputers via cable

Powerline cable Powerline cable — — use electrical lines in houseuse electrical lines in house

Phoneline Phoneline — use — use telephone linestelephone lines

Communications ChannelWhat is a communications channel?

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Transmission media on which data travels in Transmission media on which data travels in communications systemcommunications system

BandwidthBandwidth is amount of data is amount of data that can travel over a that can travel over a communications channelcommunications channel

Transmission mediaTransmission media are materials or substances are materials or substances capable of carrying one or more capable of carrying one or more signalssignals

Communications ChannelHow is a request sent over the Internet using a communications channel?

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Physical Transmission MediaWhat is physical transmission media?

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Wire, cable, Wire, cable, and other tangible materials and other tangible materials used used to send communications to send communications signalssignals

Physical Transmission MediaWhat are twisted-pair cable and coaxial cable?

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Twisted-pair cableTwisted-pair cable is used for telephone systems and network cabling is used for telephone systems and network cabling

Coaxial cableCoaxial cable is often used for cable television wiring is often used for cable television wiring

Physical Transmission MediaWhat is fiber-optic cable?

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Capable of carrying Capable of carrying significantly more significantly more data at faster speeds data at faster speeds than wire cablesthan wire cables

Less susceptible Less susceptible to interference to interference (noise) and, therefore, (noise) and, therefore, more securemore secure

Smaller size (thinner Smaller size (thinner and lighter)and lighter)

Wireless Transmission MediaWhat is wireless transmission media?

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Used when inconvenient, impractical, or impossible to install cablesUsed when inconvenient, impractical, or impossible to install cables Includes Bluetooth and IrDAIncludes Bluetooth and IrDA

Wireless Transmission MediaWhat are broadcast radio and cellular radio?

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Broadcast radioBroadcast radio distributes radio distributes radio signals over long signals over long and short distancesand short distances

Cellular radioCellular radio is form of is form of broadcast radio broadcast radio used for mobile used for mobile communicationscommunications

Wireless Transmission MediaWhat is a microwave station?

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Earth-based Earth-based reflective reflective dish used for dish used for microwave microwave communicationscommunications

Must transmit in Must transmit in straight line with straight line with no obstructionsno obstructions

Wireless Transmission MediaWhat is a communications satellite?

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Space station Space station that receives microwave that receives microwave signals from earth-based signals from earth-based station, amplifies station, amplifies signals, and broadcasts signals, and broadcasts signals back to any signals back to any number of earth-based number of earth-based stationsstations

Network Hardware

• Network interface cards– Network adapter– Connects node to the media– Unique Machine Access Code (MAC)

Network Hardware

• Network linking devices– Connect nodes in the network– Cable runs from node to device– Crossover cable connects two computers

Network Hardware

• Hubs– Center of a star network– All nodes receive transmitted packets– Slow and insecure

Network Hardware

• Switches– Replacement for hubs– Only intended node receives transmission– Fast and secure

Network Hardware

• Bridge– Connects two or more LANs together– Packets sent to remote LAN cross

• Other packets do not cross

– Segments the network on MAC addresses

Network Hardware

• Router– Connects two or more LANs together– Packets sent to remote LAN cross– Network is segmented by IP address– Connect internal networks to the Internet– Need configured before installation

Network Hardware

• Gateway– Connects two dissimilar networks– Connects coax to twisted pair– Most gateways contained in other devices

Network Cabling

• Cabling specifications– Bandwidth measures cable speed

• Typically measured in Mbps

– Maximum cable length– Connector describes the type of plug

Network Cabling

• Ethernet– Very popular cabling technology– 10 Base T, 10Base2, 10Base5– Maximum bandwidth 10 Mbps– Maximum distances100 to 500 meters

Network Cabling

• Fast Ethernet– Newer version of Ethernet– Bandwidth is 100 Mbps– Uses Cat5 or greater cable

• Sometimes called 100Base T

– Requires a switch

Network Cabling

• Gigabit Ethernet– High bandwidth version of Ethernet– 1 to 10 Gbps– Cat 5 or fiber optic cable– Video applications

Network Cabling

• Token ring– Uses shielded twisted pair cabling– Bandwidth between 10 and 25 Mbps– Uses a multiple access unit (MAU)– Popular in manufacturing and finance

Network Protocols

• Language of the network– Rules of communication– Error resolution– Defines collision and collision recovery– Size of packet– Naming rules for computers

Network Protocols

• TCP/IP– Transmission Control Protocol/Internet

Protocol– Most popular protocol– Machines assigned a name of 4 numbers

• IP address• 209.8.166.179 is the White House’s web site

– Dynamic Host Configuration Protocol• Simplifies assignment of IP addresses

– Required for Internet access

Network Protocols

• IPX/SPX– Internet Packet Exchange/Sequenced

Packet Exchange– Older protocol– Associated with Novell Netware– Replaced by TCP/IP

Network Protocols

• NetBEUI– Network BIOS Extended User Interface– Used by Windows to name computers– Transmission details handled by TCP/IP

Network Protocols

• Token ring– Nodes communicate when they have the

token– Popular in manufacturing and finance

Modem Communications

• Plain Old Telephone System (POTS)– Standard phone line– Two-way voice communication– Uses analog transmission techniques– Data communication is slow

Modem Communications

• Modems– Modulator/Demodulator

• Modulator converts digital to analog

– Speed measured in bits per second (bps)• Current fastest speed is 56 Kbps• Quality of phone lines dictates speed

– V.92 is the current modem standard– Several modem types

• Internal• External• Voice• Fax

Modem Communications• Modem uses

– Connection to the Internet– File transfer

• Uploading• Downloading

Digital Data Connections

• Digital phone lines– Local telephone companies are upgrading– Service will faster and more reliable– New phones will be needed– Modems will need to be upgraded

Digital Data Connections

• Broadband connection– Any data connection faster than 56 Kbps– Common in business– Becoming popular in home installations

Digital Data Connections

• ISDN lines– Integrated Services Digital Network– Basic rate uses three channels

• Two data channels each support 64 Kbps• Error correction channel

– Primary rate uses 24 data channels

ISDN Connection

Digital Data Connections

• T lines– High-capacity voice/data lines– Used to control phone and data– Several variants– T1 transmits at 1.544 Mbps– T3 transmits at 44.736 Mbps

Digital Data Connections

• DSL technologies– Digital Subscriber Line– Popular with home users– Speeds range from 100 Kbps to 30 Mbps– Asymmetrical DSL (ADSL)

• Upload speed slower than download speed

– Symmetrical DSL (SDSL)– Requires a DSL modem

Digital Data Connections

• Cable modem connections– Popular with home and office users– Speeds between 1 and 3 Mbps– Requires a cable modem

Digital Data Connections

• ATM– Asynchronous Transfer Mode– Efficient transfer of video and sound– Requires a special NIC and hardware

Consumer E-Commerce

• Online shopping– Purchasing through a web site– Also called Business to Consumer (B2C)– List of products is nearly endless– Features

• Searchable catalog• Secure checkout• Customer support page

Consumer E-Commerce

• Online stores versus brick and mortar– Brick and mortar implies a physical store– Brick and mortar properties

• Limited hours• Salespeople can offer assistance• Customers can handle the merchandise

– Online store properties• Store is open 24 x 7• Salespeople usually not available• Can only view the merchandise

Online vs. Brick and Mortar

Online store catalogOnline store catalog Brick and mortar store experienceBrick and mortar store experience

Consumer E-Commerce

• Using online catalogs– Good online stores have a catalog– Products are often arranged by category– Products can be found by keyword

Consumer E-Commerce

• Paying for purchases– Vendors accept several payment methods

• Credit cards• Paypal• Electronic Fund Transfer

– May need to create an account• Simplifies shipping• Encourages repeat shopping

Consumer E-Commerce

• Getting customer service– Needed to resolve problems– Understand the policies before ordering– Contact information

• How you contact the vendor

– Return policies• Availability and fee for returning items

– Shipping policies– Charges and fees

• Convenience fees

Consumer E-Commerce

• Online banking– Most teller services handled online– Balances can be obtained– Bills can be paid– Access is typically very secure– Not available at all banks

Consumer E-Commerce

• Online finance– Broker and investment services– Costs less than a traditional broker– Stocks and bonds can be traded– Loans can be procured– Tax returns can be filed

Business E-Commerce

• Business to business (B2B)– Business transaction between companies– Accounts for the majority of e-commerce– Initially private networks were used– Common transactions

• Reorder inventory• Purchase stocks• Credit checks

Business E-Commerce

• Intranets and extranets– Business partners must work together

• Networks must work together

– Intranet uses Internet technologies• Only internal workers can access resources• Use a standard browser to access resources

– Extranets open the Intranet to clients• Clients have password level access• Allows the same abilities as employees

– Very simple to use and setup

Business E-Commerce

• Telecommuters– Employee working outside of the office– Connects to the office through technology– Several technologies are used

• Home computer and the Internet• Key card changes passwords often• Encryption is used to protect data

Security

• Improved security measures– Before 1998, Web security was nonexistent– Now safer than restaurant purchases– All reputable sites protect their customers

Security• Secure web pages

– Allows safe transmission of credit card – Use the secure socket layer (SSL)

• Encrypts data transmission to the server– Secure pages are easily identified

• URL uses https://• Browser status bar shows a closed lock