1 e- business ninth edition chapter 3 web server and e-mail technologies

1

E- BUSINESSE- BUSINESSNINTH EDITIONNINTH EDITION

Chapter 3Chapter 3Web Server and E-Mail Web Server and E-Mail

TechnologiesTechnologies

E- Business, Ninth Edition 2

LEARNINGLEARNING OBJECTIVES OBJECTIVES

In this chapter, you will learn aboutIn this chapter, you will learn about::Web server basicsWeb server basicsSoftware for Web serversSoftware for Web serversE-mail management and spam E-mail management and spam control issuescontrol issues

Internet and Web site utility Internet and Web site utility programsprograms

Web server hardwareWeb server hardware2

WEB SERVER BASICSWEB SERVER BASICSChapter TopicsChapter Topics

Basic Technologies To Build Online Business Basic Technologies To Build Online Business Web SitesWeb Sites Server Software And HardwareServer Software And Hardware Utility Function SoftwareUtility Function Software

Client/Server ArchitecturesClient/Server ArchitecturesUsed In Lans, Wans, And The WebUsed In Lans, Wans, And The WebClient Requests Server ServicesClient Requests Server Services

ServersServersHave More Memory And Larger, Faster Disk Have More Memory And Larger, Faster Disk

DrivesDrivesE- Business, Ninth Edition 3

WEB SERVER BASICS…WEB SERVER BASICS…

Web Browser SoftwareWeb Browser SoftwareUses Web Browser Software (Web Uses Web Browser Software (Web Client Software)Client Software)

Make Computers Work As Web ClientsMake Computers Work As Web ClientsWeb Browser Also Called Web Client Web Browser Also Called Web Client SoftwareSoftware

Platform NeutralPlatform NeutralCritical in rapid spread and Critical in rapid spread and widespread Web acceptancewidespread Web acceptance


4


FIGURE 3-1: Platform Neutrality Of The Web

WEB SERVER BASICS…WEB SERVER BASICS…Web ServerWeb Server

Main Job: Respond to Web client Main Job: Respond to Web client requestsrequests

Main Elements:Main Elements: Hardware, Operating System Hardware, Operating System

Software, Web Server SoftwareSoftware, Web Server SoftwareWeb Site Goals Followed By Site Web Site Goals Followed By Site

Development EstimationsDevelopment EstimationsNumber of VisitorsNumber of VisitorsNumber of Pages Viewed During an Number of Pages Viewed During an

Average VisitAverage VisitHow Large Pages Will Be How Large Pages Will Be Maximum Number Of Simultaneous Maximum Number Of Simultaneous

VisitorsVisitorsE- Business, Ninth Edition 6

DYNAMIC CONTENT GENERATIONDYNAMIC CONTENT GENERATION

Dynamic PageDynamic PageWeb page content shaped by program Web page content shaped by program

Static PageStatic PageUnchanging page retrieved from Web Unchanging page retrieved from Web

server file(s)server file(s)Web Sites Using Collection Of HTML PagesWeb Sites Using Collection Of HTML Pages

Changed by editing HTML (cumbersome)Changed by editing HTML (cumbersome) Specific query-customized pages not Specific query-customized pages not

allowedallowedDynamic ContentDynamic Content

Nonstatic information constructed in Nonstatic information constructed in response to Web client’s requestresponse to Web client’s request

Gives user an interactive experienceGives user an interactive experienceE- Business, Ninth Edition 7

DYNAMIC CONTENT DYNAMIC CONTENT GENERATION…GENERATION…Approaches For Creating Dynamic ContentApproaches For Creating Dynamic Content

Client-Side ScriptingClient-Side Scripting Software operates on the Web client (browser)Software operates on the Web client (browser) Software changes Web page display in Software changes Web page display in

response to a user’s actionsresponse to a user’s actions Software examples: JavaScript or Adobe FlashSoftware examples: JavaScript or Adobe Flash

Server-Side ScriptingServer-Side Scripting Program runs on a Web serverProgram runs on a Web server Program creates Web page in response to Program creates Web page in response to

request for specific information from a Web request for specific information from a Web clientclient


Dynamic Page Generation TechnologiesDynamic Page Generation TechnologiesServer-side Scripts Mixed With Html-tagged Server-side Scripts Mixed With Html-tagged

TextTextExamples:Examples:

Microsoft Microsoft Active Server Pages Active Server Pages ((ASPASP): ): ASP.NETASP.NET

Sun Microsystems Sun Microsystems JavaServer Pages JavaServer Pages ((JSPJSP): ): Java servletsJava servlets

Open-source Apache Software Foundation Open-source Apache Software Foundation Hypertext Preprocessor (PHP)Hypertext Preprocessor (PHP)

Adobe Adobe Cold FusionCold FusionServer-side Languages generally use: Server-side Languages generally use:

Common Gateway InterfaceCommon Gateway Interface ( (CGICGI))E- Business, Ninth Edition 9

DYNAMIC CONTENT DYNAMIC CONTENT GENERATION…GENERATION…

Dynamic Page Generation ToolsDynamic Page Generation ToolsAJAXAJAX (Asynchronous JavaScript and (Asynchronous JavaScript and

XML)XML) Creates interactive Web sites looking Creates interactive Web sites looking

like applicationslike applications Example: Google MapsExample: Google Maps

Ruby on RailsRuby on Rails Creates dynamic Web pages with Creates dynamic Web pages with

interface looking like applicationinterface looking like applicationPythonPython

Scripting languageScripting languageE- Business, Ninth Edition 10

DYNAMIC CONTENT DYNAMIC CONTENT GENERATION…GENERATION…

VARIOUS MEANINGS OF “SERVER”VARIOUS MEANINGS OF “SERVER”

ServerServerComputer providing files, making programs Computer providing files, making programs

available to other computers connected to it available to other computers connected to it through a networkthrough a network

Software used to make files and programs Software used to make files and programs availableavailable May be part of the operating system (OS)May be part of the operating system (OS) Server OS software may be referred to as Server OS software may be referred to as

server software (confusing)server software (confusing)May connect through a router to the May connect through a router to the

InternetInternet Run Web server softwareRun Web server software


VARIOUS MEANINGS OF “SERVER” VARIOUS MEANINGS OF “SERVER” ……

Web ServerWeb ServerComputer connected to the InternetComputer connected to the InternetRuns Web server softwareRuns Web server software

Makes server’s files available to other Makes server’s files available to other computerscomputers

E-mail Server: Handles incoming, outgoing e-E-mail Server: Handles incoming, outgoing e-mailmail

Database ServerDatabase ServerRuns database management softwareRuns database management software

““Server” describes several types of computer Server” describes several types of computer hardware, softwarehardware, softwareNote context for a better understandingNote context for a better understanding


WEB CLIENT/SERVER WEB CLIENT/SERVER ARCHITECTURESARCHITECTURES

Web browser requests files from Web serverWeb browser requests files from Web serverTransportation medium: the InternetTransportation medium: the InternetRequest formatted by browser using HTTPRequest formatted by browser using HTTPRequest sent to server computerRequest sent to server computerServer receives requestServer receives request

Retrieves file containing requested Web Retrieves file containing requested Web pagepage

Formats using HTTPFormats using HTTP Sends back to client over the InternetSends back to client over the Internet

Client Web browser softwareClient Web browser software Displays page on client machineDisplays page on client machine


WEB CLIENT/SERVER WEB CLIENT/SERVER ARCHITECTURES…ARCHITECTURES…Repeating ProcessRepeating Process

Client requests, server responds, client Client requests, server responds, client displays resultdisplays result

Possible result:Possible result: Dozens or even hundreds of separate Dozens or even hundreds of separate

server responsesserver responsesGraphics and other objectsGraphics and other objects

May be slow to appear in client’s Web May be slow to appear in client’s Web browser windowbrowser window

Two-tier Client/Server ArchitectureTwo-tier Client/Server ArchitectureOne client and one server computerOne client and one server computer

Create and read messagesCreate and read messages


14


FIGURE 3-2: Message Flows In A Two-tier Client/Server Network

Request MessageRequest MessageWeb client message sent to request file(s) Web client message sent to request file(s)

from a Web serverfrom a Web serverThree Major PartsThree Major Parts

Request lineRequest line: contains command, target : contains command, target resource name, protocol name, version resource name, protocol name, version numbernumber

Optional Optional request headersrequest headers: file type : file type information client acceptsinformation client accepts

Optional Optional entity bodyentity body: passes bulk : passes bulk information to serverinformation to server


WEB CLIENT/SERVER WEB CLIENT/SERVER ARCHITECTURES…ARCHITECTURES…

Server Receiving Request Message Executes Server Receiving Request Message Executes Command Included In MessageCommand Included In MessageRetrieves Web page file from diskRetrieves Web page file from diskCreates Creates response messageresponse message: Sent back to client: Sent back to client

Identical in structure to request message Identical in structure to request message (slightly different function)(slightly different function)

Response header lineResponse header line: server HTTP version, : server HTTP version, response status, status information response status, status information explanationexplanation

Response header fieldResponse header field: information : information describing server’s attributesdescribing server’s attributes

Entity bodyEntity body: returns HTML page requested: returns HTML page requested



Three-Tier ArchitectureThree-Tier ArchitectureExtends two-tier architectureExtends two-tier architecture

Allows additional processing before Allows additional processing before server responds to client’s requestserver responds to client’s request

Often includes databases and related Often includes databases and related software applicationssoftware applications Supplies information to the Web serverSupplies information to the Web server

Web server uses software applications’ Web server uses software applications’ output when responding to client output when responding to client requestsrequests




FIGURE 3-3 Message Flows In A Three-tier Client/Server Network

E- Business, Ninth Edition

n-tier Architecturesn-tier ArchitecturesMore than three tiersMore than three tiersExample: catalog-style Web site search, Example: catalog-style Web site search,

update, display functionsupdate, display functions Track customer purchases stored in Track customer purchases stored in

shopping carts, look up sales tax rates, shopping carts, look up sales tax rates, keep track of customer preferences, keep track of customer preferences, query inventory databases, keep query inventory databases, keep company catalog currentcompany catalog current

20


SOFTWARE FOR WEB SOFTWARE FOR WEB SERVERSSERVERS

Web server software may:Web server software may:Run on one or several computer operating Run on one or several computer operating

systemssystems

Section TopicsSection TopicsLearn about operating system software used Learn about operating system software used

on most Web serverson most Web serversLearn about Web server software itselfLearn about Web server software itselfLearn about other programsLearn about other programs

Running on Web servers or other Running on Web servers or other computers as part of electronic commerce computers as part of electronic commerce operationsoperations


OPERATING SYSTEMS FOR WEB OPERATING SYSTEMS FOR WEB SERVERS SERVERS

Operating System TasksOperating System TasksRunning programs, allocating computer Running programs, allocating computer

resources, providing input and output servicesresources, providing input and output servicesLarger system responsibilitiesLarger system responsibilities

Tracking multiple users, ensuring no Tracking multiple users, ensuring no interferenceinterference

Web Server Operating Systems SoftwareWeb Server Operating Systems SoftwareMicrosoft Windows Server productsMicrosoft Windows Server productsLinuxLinuxUNIX-based operating systemsUNIX-based operating systems

FreeBSD or Sun’s SolarisFreeBSD or Sun’s SolarisE- Business, Ninth Edition 22

OPERATING SYSTEMS FOR WEB OPERATING SYSTEMS FOR WEB SERVERS …SERVERS …

Microsoft Server ProductsMicrosoft Server ProductsConsidered Simple To Learn and useConsidered Simple To Learn and useRaise security concernsRaise security concerns

LinuxLinuxOpen-sourceOpen-sourceFast, efficient, easy to installFast, efficient, easy to installCan be downloaded free from the WebCan be downloaded free from the WebMost companies buy it through a Most companies buy it through a

commercial distributorcommercial distributor Includes additional utilities, supportIncludes additional utilities, support


23

Linux (cont’d.)Linux (cont’d.)Commercial Linux examples: Commercial Linux examples:

Mandriva, Red Hat, SCO Group, SuSE Mandriva, Red Hat, SCO Group, SuSE

Linux EnterpriseLinux Enterprise

Unix-based Operating SystemUnix-based Operating SystemSolarisSolaris


OPERATING SYSTEMS FOR WEB OPERATING SYSTEMS FOR WEB SERVERS …SERVERS …

WEB SERVER SOFTWAREWEB SERVER SOFTWARE

Commonly Used Web Server ProgramsCommonly Used Web Server ProgramsApache HTTP Server, Microsoft Internet Apache HTTP Server, Microsoft Internet

Information Server (IIS), Sun Java System Information Server (IIS), Sun Java System Web Server (JSWS)Web Server (JSWS)

Netcraft December 2009 Web survey indicates:Netcraft December 2009 Web survey indicates:Web server software market share stabilized Web server software market share stabilized

in recent yearsin recent years

Web Server Performance DifferencesWeb Server Performance DifferencesWorkload, Operating System, Web Pages Workload, Operating System, Web Pages

ServedServed



FIGURE 3-4: Percent Of Web Active Sites That Use Major Web Server Software Products

WEB SERVER SOFTWARE …WEB SERVER SOFTWARE …Apache HTTP ServerApache HTTP Server

1994: Rob McCool developed Apache1994: Rob McCool developed ApacheExtension had original core system with Extension had original core system with

patchespatches Known as “a patchy” server (“Apache”)Known as “a patchy” server (“Apache”)

Reasons Apache dominated Web since 1996Reasons Apache dominated Web since 1996 Free and performs efficientlyFree and performs efficiently

Runs on many operating systems and Runs on many operating systems and supporting hardwaresupporting hardware FreeBSD-UNIX, HP-UX, Linux, Microsoft FreeBSD-UNIX, HP-UX, Linux, Microsoft

Windows, SCO-UNIX, and SolarisWindows, SCO-UNIX, and SolarisE- Business, Ninth Edition 27

Microsoft Internet Information ServerMicrosoft Internet Information ServerBundled with Microsoft Windows Server OSBundled with Microsoft Windows Server OSUsed on many corporate intranetsUsed on many corporate intranetsUsed by small and large sitesUsed by small and large sitesRun only on Windows server operating Run only on Windows server operating

systems (by design)systems (by design)Supports ASP, ActiveX Data Objects, SQL Supports ASP, ActiveX Data Objects, SQL

database queriesdatabase queriesProduces dynamic Web pages by:Produces dynamic Web pages by:

Including HTML pages, ActiveX Including HTML pages, ActiveX components, scriptscomponents, scripts


WEB SERVER SOFTWARE …WEB SERVER SOFTWARE …

Sun Java System Web ServerSun Java System Web ServerOriginal NCSA Web server program Original NCSA Web server program

descendentdescendentFormer names: Sun ONE, Netscape Former names: Sun ONE, Netscape

Enterprise Server, iPlanet Enterprise Enterprise Server, iPlanet Enterprise

ServerServer2009: key elements became open 2009: key elements became open

sourcesourceRuns on many operating systems:Runs on many operating systems:

HP-UX, Solaris, WindowsHP-UX, Solaris, WindowsE- Business, Ninth Edition 29



Sun Java System Web Server (cont’d.)Sun Java System Web Server (cont’d.)Runs on about 1 percent of all Web Runs on about 1 percent of all Web

serversserversRuns on some of the busiest serversRuns on some of the busiest servers

BMW, Dilbert, E*TRADE, Excite, Lycos, BMW, Dilbert, E*TRADE, Excite, Lycos,

SchwabSchwabSupports dynamic application Supports dynamic application

development for server-side applicationsdevelopment for server-side applicationsProvides connectivity to a number of Provides connectivity to a number of

database productsdatabase products30


FINDING WEB SERVER SOFTWARE FINDING WEB SERVER SOFTWARE INFORMATIONINFORMATION

Netcraft Web SiteNetcraft Web Site““What’s that site running?” linkWhat’s that site running?” link

Leads to search function pageLeads to search function pageProvides operating system, Web Provides operating system, Web

server software specific site now server software specific site now

runningrunningProvides past site informationProvides past site information


ELECTRONIC MAIL (E-MAIL)ELECTRONIC MAIL (E-MAIL)

Electronic Commerce Important TechnologiesElectronic Commerce Important TechnologiesWebWeb

Provides interactions between Web Provides interactions between Web servers and clientsservers and clients

E-mail:E-mail: Used to gather information, execute Used to gather information, execute

transactions, perform other electronic transactions, perform other electronic commerce related taskscommerce related tasks

Originated from ARPANETOriginated from ARPANET Most popular form of business Most popular form of business

communicationcommunication


E-MAIL BENEFITSE-MAIL BENEFITSReason People Originally Attracted To The Reason People Originally Attracted To The

InternetInternetConveys messages in secondsConveys messages in seconds

Contains simple ASCII text or character Contains simple ASCII text or character formattingformatting

Useful FeatureUseful FeatureAttachmentsAttachments: most important message part: most important message part

E-mail UsesE-mail UsesConfirm receipt of customer orders, confirm Confirm receipt of customer orders, confirm

shipment of items ordered, send information shipment of items ordered, send information about a purchase to buyer, announce specials about a purchase to buyer, announce specials and sales, keep in touch with customersand sales, keep in touch with customers


E-MAIL DRAWBACKSE-MAIL DRAWBACKSTime Spent Answering E-mailTime Spent Answering E-mail

Managers: five minutes per e-mailManagers: five minutes per e-mailAverage person: two hours a dayAverage person: two hours a dayCreating resentmentCreating resentment

Computer Virus (Virus)Computer Virus (Virus)Program attaching itself to another programProgram attaching itself to another program

Causes damage when host program Causes damage when host program activatedactivated

Attachment can contain virusesAttachment can contain virusesCost for e-mail convenienceCost for e-mail convenience

Virus protection software, dealing with Virus protection software, dealing with security threatssecurity threats


SPAMSPAMMagnitude Of Spam Problem Magnitude Of Spam Problem

Recent 24-hour period showed 220 Recent 24-hour period showed 220 billion spam e-mail messages sentbillion spam e-mail messages sent

Researchers believe spam growth has Researchers believe spam growth has leveled offleveled off Appears to be declining slightlyAppears to be declining slightly

Until effective technical solutions Until effective technical solutions implementedimplemented 90 percent of all e-mail messages will 90 percent of all e-mail messages will

continue to be spamcontinue to be spamE- Business, Ninth Edition 35


FIGURE 3-5: Growth Of Spam As A Proportion Of All Business E-mail

SPAM …SPAM …Antispam Efforts And Software Antispam Efforts And Software ProductsProductsE-mail server softwareE-mail server software

Limit amount of spam getting to Limit amount of spam getting to employeesemployees

Client-based spam-filtering programsClient-based spam-filtering programsSet filters available within client e-mail Set filters available within client e-mail

client softwareclient softwareMost effectiveMost effective

Eliminate spam before downloaded to Eliminate spam before downloaded to useruser



SOLUTIONS TO THE SPAM SOLUTIONS TO THE SPAM PROBLEMPROBLEM

Methods To Limit Spam And Its EffectsMethods To Limit Spam And Its EffectsPassing new lawsPassing new lawsTechnical changes in Internet mail-handling Technical changes in Internet mail-handling

systemssystemsUse existing laws and current technologiesUse existing laws and current technologies

Requires cooperation from large numbers Requires cooperation from large numbers of organizations and businessesof organizations and businesses

Use tactics available for individual e-mail Use tactics available for individual e-mail usersusers

38

SOLUTIONS TO THE SPAM PROBLEM …SOLUTIONS TO THE SPAM PROBLEM …Individual User Antispam TacticsIndividual User Antispam Tactics

Limit spammers access to e-mail Limit spammers access to e-mail addressaddress

Use complex e-mail address Use complex e-mail address [email protected]@mycompany.com

Control e-mail address exposureControl e-mail address exposure Spammer software robots search for e-Spammer software robots search for e-

mail addressesmail addresses Discussion boards, chat rooms, other Discussion boards, chat rooms, other

online sourcesonline sourcesUse multiple e-mail addressesUse multiple e-mail addresses

Switch to another if spammers use oneSwitch to another if spammers use oneUse filtering techniquesUse filtering techniques

Based on contentsBased on contentsE- Business, Ninth Edition 39

Basic Content FilteringBasic Content FilteringContent-filtering techniques differ in terms Content-filtering techniques differ in terms

of:of: Content elements examinedContent elements examined Spam indications Spam indications How strictly message classification rules How strictly message classification rules

appliedappliedBasic content filters examine e-mail headersBasic content filters examine e-mail headersFiltering task software locationFiltering task software location

Client-level filteringClient-level filtering: individual users’ : individual users’ computerscomputers

Server-level filteringServer-level filtering: mail server : mail server computerscomputers


SOLUTIONS TO THE SPAM PROBLEM …SOLUTIONS TO THE SPAM PROBLEM …

Basic Content Filtering Basic Content Filtering (cont’d.)(cont’d.)Black list spam filterBlack list spam filter

Looks for known spammers in incoming Looks for known spammers in incoming messages’ From addressesmessages’ From addresses

White list spam filterWhite list spam filter Looks for good sender From addresses in Looks for good sender From addresses in

incoming messagesincoming messages High High false positives false positives raterate

Used in client-level or server-level filtersUsed in client-level or server-level filters Can also use approaches together with Can also use approaches together with

other content-filtering approachesother content-filtering approaches



Challenge-response Content FilteringChallenge-response Content FilteringCompares all incoming messages to a white Compares all incoming messages to a white

listlist If sender not on white list, automated e-If sender not on white list, automated e-

mail response sent (challenge)mail response sent (challenge) Challenge asks sender to reply to e-mail Challenge asks sender to reply to e-mail

(response)(response) Reply must contain response to a Reply must contain response to a

challenge presented in the e-mailchallenge presented in the e-mailDesigned so human can respond easilyDesigned so human can respond easilyMore informationMore information

Carnegie Mellon University CAPTCHA Carnegie Mellon University CAPTCHA Project siteProject site




• DrawbacksDrawbacks

• Potential abusePotential abuse

• Doubles amount of useless e-mail messages sentDoubles amount of useless e-mail messages sent

FIGURE 3-6: Example Of A Challenge That Uses Distorted Letters And Numbers


Advanced Content FilteringAdvanced Content FilteringMore effective than basic content filtersMore effective than basic content filtersLooks for spam indicators in entire e-mail Looks for spam indicators in entire e-mail

messagemessage Indicator identified: message’s spam Indicator identified: message’s spam

“score” raised“score” raisedIndicator TypesIndicator Types

Words, word pairs, certain HTML codes, Words, word pairs, certain HTML codes, information about where word occursinformation about where word occurs

ProblemsProblems Spammers stop including defined Spammers stop including defined

indicatorsindicatorsE- Business, Ninth Edition 44


Advanced Content Filtering (cont’d.)Advanced Content Filtering (cont’d.)Bayesian Revision Statistical TechniqueBayesian Revision Statistical Technique

Additional knowledge used to revise earlier Additional knowledge used to revise earlier probability estimatesprobability estimates

Naïve Bayesian Filter Naïve Bayesian Filter Software begins by not classifying Software begins by not classifying

messagesmessages User reviews messagesUser reviews messages Message type indicated to software: spam Message type indicated to software: spam

(not spam)(not spam) Software gradually learns message Software gradually learns message

elementelementE- Business, Ninth Edition 45


Advanced content filtering (cont’d.)Advanced content filtering (cont’d.)Naïve Bayesian Filter Success RatesNaïve Bayesian Filter Success Rates

Few dozen messages classified: 80 percent Few dozen messages classified: 80 percent effectiveeffective

Eventually: effective rate rises above 95 Eventually: effective rate rises above 95 percentpercent

2002: POPFile Released2002: POPFile Released First functional Bayesian filter product for First functional Bayesian filter product for

individualsindividuals Open-source software development projectOpen-source software development project Installs on individual client computersInstalls on individual client computers Works with many different e-mail clients: Post Works with many different e-mail clients: Post

Office Protocol (POP) connection requiredOffice Protocol (POP) connection requiredE- Business, Ninth Edition 46



FIGURE 3-7: Training Screen In The POPFile Naïve Bayesian Filter


FIGURE 3-8: POPFile Summary Statistics Page

Advanced Content Filtering (cont’d.)Advanced Content Filtering (cont’d.)POPFile SuccessPOPFile Success

Initially caught 30 percent of spam Initially caught 30 percent of spam messagesmessages

After two weeks: caught more than 90 After two weeks: caught more than 90 percentpercent

Eventually: caught more than 99 Eventually: caught more than 99 percentpercent

False positives: small rateFalse positives: small ratePOPFile Magnet FeaturePOPFile Magnet Feature

Implement white and black list filteringImplement white and black list filteringNaïve Bayesian Filters’ EffectivenessNaïve Bayesian Filters’ Effectiveness

Very effective client-level filtersVery effective client-level filters Major drawback: users must update Major drawback: users must update

filters regularlyfilters regularlyE- Business, Ninth Edition 49


Legal SolutionsLegal SolutionsJanuary 2004: U.S. CAN-SPAM law went into January 2004: U.S. CAN-SPAM law went into

effecteffect Spam decreased first three monthsSpam decreased first three months

After no threat of broad federal After no threat of broad federal prosecution:prosecution: Spam rates increased Spam rates increased

CAN-SPAM Regulates:CAN-SPAM Regulates: All e-mail messagesAll e-mail messages Messages advertising or promoting Messages advertising or promoting

commercial product or servicecommercial product or service Messages promoting Web site contentMessages promoting Web site content



SOLUTIONS TO THE SPAM SOLUTIONS TO THE SPAM PROBLEM (CONT’D.)PROBLEM (CONT’D.)

Legal SolutionsLegal Solutions (cont’d.) (cont’d.)CAN-SPAMCAN-SPAM

Prohibits misleading e-mail message Prohibits misleading e-mail message address header information, e-mail address header information, e-mail address transferaddress transfer

Possible $11,000 fine and Possible $11,000 fine and imprisonmentimprisonment

More CAN-SPAM informationMore CAN-SPAM information U.S. Federal Trade Commission CAN-U.S. Federal Trade Commission CAN-

SPAM LawSPAM Law information pagesinformation pagesE- Business, Ninth Edition 51

FIGURE 3-9: U.S. Federal Trade Commission Spam Information Site Home Page


Legal Solutions Legal Solutions (cont’d.)(cont’d.)Reasons spam continuingReasons spam continuing

Spammers simply continue violating laws: no Spammers simply continue violating laws: no fear of prosecutionfear of prosecution

Mail servers located in other countries: Mail servers located in other countries: jurisdiction unclearjurisdiction unclear

Fines or collection of damages difficult to Fines or collection of damages difficult to obtainobtain

Spammers evade cease-and-desist orders: Spammers evade cease-and-desist orders: move operations from one server to another move operations from one server to another (in minutes)(in minutes)

Spammers hijack servers to forward mailSpammers hijack servers to forward mail FTC refused to create do-not-spam listFTC refused to create do-not-spam list



Legal Solutions Legal Solutions (cont’d.)(cont’d.)Spam elimination requires cost-Spam elimination requires cost-effective prosecutioneffective prosecution

Cost effective when:Cost effective when:Spammers identified easily Spammers identified easily

Best way to make spammers easier Best way to make spammers easier to findto findMake technical changes in the e-Make technical changes in the e-mail transport mechanismmail transport mechanism



Technical SolutionsTechnical SolutionsInternet Design Not Intended For Today's NeedsInternet Design Not Intended For Today's Needs

E-mail: incidental afterthoughtE-mail: incidental afterthought No mechanisms ensuring e-mail sender No mechanisms ensuring e-mail sender

identityidentityInternet’s Polite Set of RulesInternet’s Polite Set of Rules

Send and wait for Acknowledgement (Fast)Send and wait for Acknowledgement (Fast)Slowing down acknowledgment messagesSlowing down acknowledgment messages

Originating computer will slow (must Originating computer will slow (must continue to scan for acknowledgment)continue to scan for acknowledgment)

Will not send more messages until Will not send more messages until acknowledgment receivedacknowledgment received



Technical Solutions Technical Solutions (cont’d.)(cont’d.)Slowing down acknowledgment messages Slowing down acknowledgment messages

(cont’d.)(cont’d.) Requires defending company to develop Requires defending company to develop

way to identify computers sending spamway to identify computers sending spamIBM software: access to large database IBM software: access to large database

tracking such computers tracking such computers Other vendors: software identifying Other vendors: software identifying

multiple e-mail messages from single multiple e-mail messages from single source in rapid successionsource in rapid succession

Once identified: software delays sending Once identified: software delays sending message acknowledgmentmessage acknowledgment



Technical Solutions Technical Solutions (cont’d.)(cont’d.)TeergrubingTeergrubing: Launching a return attack: Launching a return attack

Sending e-mail messages back to Sending e-mail messages back to computer originating suspected spamcomputer originating suspected spam

Teergrubing ObjectiveTeergrubing Objective Ensure computer sending spam is trappedEnsure computer sending spam is trapped Drag down ability to send spamDrag down ability to send spam Concern: counterattack might violate lawsConcern: counterattack might violate laws

Ultimate Spam ProblemUltimate Spam Problem New e-mail protocols providing absolute New e-mail protocols providing absolute

verification of e-mail message sourceverification of e-mail message sourceE- Business, Ninth Edition 57


WEB SITE UTILITY WEB SITE UTILITY PROGRAMSPROGRAMS

TCP/IP Supports Utility Programs (Tools)TCP/IP Supports Utility Programs (Tools)Run on Web server or client computersRun on Web server or client computers

Earliest Internet Utility ProgramEarliest Internet Utility ProgramE-mailE-mail

Most important utilityMost important utilityKey element in electronic commerce Key element in electronic commerce

strategiesstrategies


FINGER AND PING FINGER AND PING UTILITIESUTILITIES

Finger Program Finger Program Runs on UNIX operating systemsRuns on UNIX operating systemsProvides information about other network Provides information about other network

usersusersMany organizations disable Finger command Many organizations disable Finger command

Privacy and securityPrivacy and securityBuilt into some e-mail programsBuilt into some e-mail programs

Ping: Packet Internet GroperPing: Packet Internet GroperTests connectivity between two Internet-Tests connectivity between two Internet-

connected computersconnected computersProvides performance data about connectionProvides performance data about connectionAvailable as freeware and sharewareAvailable as freeware and shareware


TRACERT AND OTHER ROUTE-TRACERT AND OTHER ROUTE-TRACING PROGRAMSTRACING PROGRAMS

TracertTracert (TRACE RouTe) (TRACE RouTe)Sends data packets to every computer on pathSends data packets to every computer on path

Between one computer and another Between one computer and another computercomputer

Clocks packets’ round-trip timesClocks packets’ round-trip timesProvides indication of time message needs to Provides indication of time message needs to

travel from one computer to another and backtravel from one computer to another and backEnsures remote computer onlineEnsures remote computer onlinePinpoints data traffic congestionPinpoints data traffic congestionCalculates and displays:Calculates and displays:

Number of hops between computersNumber of hops between computers Time to traverse entire one-way pathTime to traverse entire one-way path


TRACERT AND OTHER ROUTE-TRACERT AND OTHER ROUTE-TRACING PROGRAMS…TRACING PROGRAMS…Tracert Tracert (cont’d.)(cont’d.)

Sends series of packets to particular destinationSends series of packets to particular destinationRouter along Internet path between originating and Router along Internet path between originating and

destination computers:destination computers: Reports IP address and time packet arrivedReports IP address and time packet arrived

Graphical user interface route-tracing programs:Graphical user interface route-tracing programs: Provides map plot of packets’ routeProvides map plot of packets’ route

Determines Internet locations with greatest delayDetermines Internet locations with greatest delayExampleExample

Visualware VisualRouteVisualware VisualRoute route-tracing programroute-tracing program



FIGURE 3-10:Tracing A Path Between Two Computers On The Internet

TELNET AND FTP TELNET AND FTP UTILITIESUTILITIES

Telnet Telnet ProgramProgramProvides remote login capabilityProvides remote login capabilityUseful if no Web interfaceUseful if no Web interfaceAvailabilityAvailability

Free Internet downloads, Microsoft Telnet.exe Free Internet downloads, Microsoft Telnet.exe Provides remote troubleshootingProvides remote troubleshootingTelnet protocolTelnet protocol:: set of rules used by Telnet set of rules used by Telnet

programprogramWeb browser Telnet clientWeb browser Telnet client

““telnet://” followed by remote host domain telnet://” followed by remote host domain name name

Telnet use decreasingTelnet use decreasingE- Business, Ninth Edition 63

TELNET AND FTP UTILITIES …TELNET AND FTP UTILITIES …

File Transfer Protocol (FTP)File Transfer Protocol (FTP)Part of TCP/IP rules defining formatsPart of TCP/IP rules defining formats

Transfer files between TCP/IP-connected Transfer files between TCP/IP-connected computerscomputers

Useful servicesUseful services Displaying remote, local computers’ Displaying remote, local computers’

directoriesdirectories Changing current client’s or server’s active Changing current client’s or server’s active

directorydirectory Creating and removing local and remote Creating and removing local and remote

directoriesdirectoriesUses TCP and its built-in error controls:Uses TCP and its built-in error controls:

To copy files accuratelyTo copy files accuratelyE- Business, Ninth Edition 64

FTP Remote Computer Access MethodsFTP Remote Computer Access MethodsFTP client programFTP client programBrowser protocol name (ftp://) before Browser protocol name (ftp://) before

remote computer domain nameremote computer domain nameFull-privilege FTPFull-privilege FTP

FTP connection to computer (user has an FTP connection to computer (user has an account)account)

Anonymous FTPAnonymous FTPGuest accountGuest account

Username: “anonymous”Username: “anonymous” Password: e-mail addressPassword: e-mail address


TELNET AND FTP UTILITIES …TELNET AND FTP UTILITIES …

INDEXING AND SEARCHING INDEXING AND SEARCHING UTILITY PROGRAMSUTILITY PROGRAMS

Search Engines Search Engines (Search Tools)(Search Tools)Search for requested documents on specific Search for requested documents on specific

site or entire Website or entire WebIndexing Program Indexing Program

Provides full-text indexingProvides full-text indexingBrowser Search MethodsBrowser Search Methods

Compare index terms to requester’s search Compare index terms to requester’s search termterm

Use complex relevance ranking rulesUse complex relevance ranking rules Advanced search engine software (Google)Advanced search engine software (Google)

Web Server Software Contains Indexing Web Server Software Contains Indexing SoftwareSoftware


DATA ANALYSIS DATA ANALYSIS SOFTWARESOFTWARE

Web Servers Capture Visitor InformationWeb Servers Capture Visitor InformationPlaced into Web Placed into Web log filelog file (grows quickly) (grows quickly)

Third-party Web Log File Analysis Third-party Web Log File Analysis Programs Summarize InformationPrograms Summarize InformationQuery log fileQuery log fileReturn gross summary information or Return gross summary information or

accumulating details accumulating details

Popular Web Log File Analysis ProgramsPopular Web Log File Analysis ProgramsAdobe Omniture, Urchin from Google, Adobe Omniture, Urchin from Google,

WebTrendsWebTrendsE- Business, Ninth Edition 67

LINK-CHECKINGLINK-CHECKING UTILITIES UTILITIES

Dead LinkDead LinkDisplays error message rather than Displays error message rather than

Web page when clickedWeb page when clickedLink CheckerLink Checker

Examines each site pageExamines each site page Reports broken, incorrect URLsReports broken, incorrect URLs

Identifies Identifies orphan filesorphan files Web site file not linked to a pageWeb site file not linked to a page

Script checking and HTML validationScript checking and HTML validation


LINK-CHECKING UTILITIES ....LINK-CHECKING UTILITIES ....

Link-Checking ProgramsLink-Checking ProgramsAdobe Dreamweaver, Elsop LinkScanAdobe Dreamweaver, Elsop LinkScan

Reverse Link Checker Reverse Link Checker Checks company’s link exchange Checks company’s link exchange

program sitesprogram sitesEnsures link exchange partners fulfilling Ensures link exchange partners fulfilling

obligationobligation Include link back to company’s Web siteInclude link back to company’s Web site

Example: LinxCopExample: LinxCop


REMOTE SERVER REMOTE SERVER ADMINISTRATIONADMINISTRATION

Remote Server AdministrationRemote Server AdministrationWeb site administrator controls Web Web site administrator controls Web

sitesiteFrom any Internet-connected From any Internet-connected

computercomputerProvides convenienceProvides convenienceExamplesExamples

Website GarageWebsite GarageNetMechanicNetMechanic


WEB SERVER HARDWAREWEB SERVER HARDWARE

Hosting Electronic Commerce Hosting Electronic Commerce

OperationsOperationsWide variety of computer brands, types, Wide variety of computer brands, types,

sizes usedsizes usedSmall companiesSmall companies

Run Web sites on desktop PCsRun Web sites on desktop PCsMost Web sitesMost Web sites

Operate on computers designed for Operate on computers designed for

site hostingsite hostingE- Business, Ninth Edition 71

SERVER COMPUTERSSERVER COMPUTERSComparing Desktop Pcs To Server ComputersComparing Desktop Pcs To Server Computers

Servers use faster and higher-capacity Servers use faster and higher-capacity hardwarehardware

CostsCostsLow-end: $800-$1,500Low-end: $800-$1,500More common: $2,000-$200,000 More common: $2,000-$200,000

Companies Selling Web Server Hardware Companies Selling Web Server Hardware Provide Web Site Configuration ToolsProvide Web Site Configuration Tools

Housing Web Server Computers Housing Web Server Computers Freestanding casesFreestanding casesInstalled in equipment racksInstalled in equipment racks


SERVER COMPUTERS…SERVER COMPUTERS…Blade Servers: Servers-on-a-card Blade Servers: Servers-on-a-card

Small: 300 installed in single 6-foot rackSmall: 300 installed in single 6-foot rack

Fundamental Web Server JobFundamental Web Server JobProcess and respond to HTTP Web client Process and respond to HTTP Web client

requestsrequests

Virtual Server (Virtual Host)Virtual Server (Virtual Host)Maintains more than one server on one Maintains more than one server on one

machinemachineDifferent groups have separate domain Different groups have separate domain

namesnames All domain names refer to same physical All domain names refer to same physical

Web serverWeb serverE- Business, Ninth Edition 73

WEB SERVER PERFORMANCE WEB SERVER PERFORMANCE EVALUATIONEVALUATION

BenchmarkingBenchmarking: Testing to compare : Testing to compare hardware and software performancehardware and software performance

Elements Affecting Overall Server Elements Affecting Overall Server PerformancePerformanceHardware, operating system software, Hardware, operating system software,

server software, connection speed, user server software, connection speed, user capacity, type of Web pages deliveredcapacity, type of Web pages delivered

Connection speed (T3 faster than T1)Connection speed (T3 faster than T1)Number of users server can handleNumber of users server can handle

Important and hard to measureImportant and hard to measureE- Business, Ninth Edition 74

WEB SERVER PERFORMANCE WEB SERVER PERFORMANCE EVALUATION …EVALUATION …ThroughputThroughput: HTTP requests hardware and : HTTP requests hardware and

software process in a unit of timesoftware process in a unit of time

Response TimeResponse Time: Time server requires to : Time server requires to process one requestprocess one request

Choosing Web Server Hardware ConfigurationsChoosing Web Server Hardware ConfigurationsRun tests on various combinations, consider Run tests on various combinations, consider

scalability, compare standard benchmarksscalability, compare standard benchmarks

Run Benchmarks RegularlyRun Benchmarks Regularly

ObjectiveObjectiveProvide site visitors with best service Provide site visitors with best service

possiblepossibleE- Business, Ninth Edition 75

WEB SERVER HARDWARE WEB SERVER HARDWARE ARCHITECTURESARCHITECTURES

Electronic Commerce Web Sites Use Tiered Electronic Commerce Web Sites Use Tiered ArchitectureArchitectureDivides work of serving Web pagesDivides work of serving Web pagesMay use more than one computer within each May use more than one computer within each

tiertierServer FarmsServer Farms: Large Collections Of Servers: Large Collections Of Servers

Lined up row after row Lined up row after row Centralized ArchitectureCentralized Architecture

Uses a few large and fast computersUses a few large and fast computers Requires expensive computers Requires expensive computers More sensitive to technical problemsMore sensitive to technical problems Requires adequate backup plansRequires adequate backup plans


WEB SERVER HARDWARE WEB SERVER HARDWARE ARCHITECTURES …ARCHITECTURES …Distributed ArchitectureDistributed Architecture

((Decentralized ArchitectureDecentralized Architecture))Uses large number of less-powerful Uses large number of less-powerful

computerscomputers Spreads risk over large number of Spreads risk over large number of

serversservers Uses less-expensive serversUses less-expensive servers Requires additional hubs or switches Requires additional hubs or switches

to connect servers to each and the to connect servers to each and the InternetInternet

Requires cost of load balancing Requires cost of load balancing E- Business, Ninth Edition 77

Load-Balancing SystemsLoad-Balancing SystemsLoad-Balancing SwitchLoad-Balancing Switch

Network hardware monitoring server Network hardware monitoring server workloadsworkloads

Assigns incoming Web traffic to the Assigns incoming Web traffic to the server with most available capacityserver with most available capacity

Simple Load-Balancing SystemSimple Load-Balancing System Traffic enters through site’s routerTraffic enters through site’s router Encounters load-balancing switchEncounters load-balancing switch Directs traffic to best Web serverDirects traffic to best Web server


WEB SERVER HARDWARE WEB SERVER HARDWARE ARCHITECTURES …ARCHITECTURES …


FIGURE 3-12: A Load-balancing System In A Decentralized Architecture

Load-Balancing Systems (cont’d.)Load-Balancing Systems (cont’d.)More Complex Load-Balancing More Complex Load-Balancing

SystemsSystems Incoming Web traffic enters from Incoming Web traffic enters from

two or more routerstwo or more routersDirected to groups of dedicated Directed to groups of dedicated

Web serversWeb servers


80

WEB SERVER HARDWARE WEB SERVER HARDWARE ARCHITECTURES …ARCHITECTURES …


81

FIGURE 3-13: Complex Load Balancing

SUMMARYSUMMARYClient/Server Web ArchitectureClient/Server Web Architecture

HTTP-based tiered architecturesHTTP-based tiered architecturesSeveral Operating Systems Used On Web ServersSeveral Operating Systems Used On Web ServersWeb Server Utility Programs Can Be HelpfulWeb Server Utility Programs Can Be HelpfulE-mail Has Benefits And DrawbacksE-mail Has Benefits And Drawbacks

Spam problem has grown dramaticallySpam problem has grown dramaticallyWeb Server Hardware Web Server Hardware

Important consideration in online business site Important consideration in online business site designdesign

Understand Web Server PerformanceUnderstand Web Server PerformanceFactors, evaluation tools, solutionsFactors, evaluation tools, solutions


1 e- business ninth edition chapter 3 web server and e-mail technologies

Documents