E-Commerce Architectures and Technologies Rob Oshana Southern Methodist University

Agenda Business Models Business to Business and Business to Consumer The beginning - Electronic Data Interchange (EDI) Network Architectures Internet and Web Architectures E-Commerce Architectures Intranet, Extranet, Internet IBM E-Commerce Success Steps

Corporation Manufacturer Indirect supplier 1 Indirect supplier 2 Business to Business Direct Suppliers Transportation of Supplies Corporation Government Manufacturer Financial Institution Sales IT Marketing Services Credit Card Processing Business to Consumer Distribution Electronic Store Front UPS/Fedex

Layered Architecture for eBusiness Electronic Commerce Applications (Supply chain management, video on demand, on-line marketing and advertising, home shopping) Common Business Services Infrastructure (security/authentication, electronic payment, directories/catalog) Messaging and information distribution infrastructure (EDI, e-mail, HTTP) Multimedia content and network publishing infrastructure (HTML, Java, WWW) Network Infrastructure (telecom, cable TV, wireless, internet)

Vendor Centric Versus Customer Centric Customer A Customer B Vendor Vendor Centric Customer C Customer D Vendor A Vendor B Customer Customer Centric Vendor C Vendor D

Web Architecture Firewall Buyer Supplier Supplier connection Server Internal External Server User Buyer Procurement Browser Intranet Browser Server Internal Admin Intranet Functional Units User Production Other Supplier Firewall Supplier User Internet connection Functional Units Server External Browser Intranet Web Architecture Server External Server Internal

The Web Commercial Community Consumer Software Developers University Quicken Online resources Search Engines Simulations GDSS Mutual Fund DB Online Magazines Web catalogs Virtual Reality Web DBMS Online Services Payment System Bank WebAd Manager Products on the Web Cybermediaries Web compatible software Supplier Delivery Service

Web-based Transactions Web Business Community Buyer Seller 1. Select product via browsers. 1. Provide product and pricing information. 2. Update info periodically. 3. Buyer pays by credit cards Payment System Browser 2. Put selected merchandise into shopping cart. 5. Ship product to buyer 4. Authorization from bank or credit card company ProductAd Manager Web catalog system Manages product ad etc. Bank Web Catalog Product Product

Components of the Web DB Web Browser TCP/IP based network (HTTP) CGI Content Web Clients Web Servers (web pages) Software applications 1. Browser establishes connection with server. 2. Browser issues request to server. 3. Server sends a response (page or graphics) 4. Both browser and server disconnect and the transaction ends. Common Gateway Interface (CGI) CGI defines how external applications can interact with Web servers HTML describes the contents of each Web page

Business-to-Business and Business-to-Consumer

Business-to-Business The selling of products and services between corporations and the automation of systems via integration Typical players involved suppliers distributors manufacturers stores

Business-to-Business Most of the transactions occur directly between two systems automation of the supply chain Supply Chain Management; the process of tying together multiple suppliers of goods to create a final product Daimler-Chrysler Corporation over 20,000 suppliers of parts SPIN B2B solution increased productivity over 20% in first year

Business-to-Business Other forms of B2B E-Commerce Malls QVC; offers a common interface for buyers to access different supppliers Buyers manage their own back end DBs (product information) Helps retailers collaborate with worldwide supply chain www.qvc.com

Business-to-Business Other forms of B2B E-Commerce Catalogs Used for purchases between companies Allow corporate buyers to search for products based on features or price Single interface for individual sellers or multiple sellers of similar products Benefits include ease of use flexibility easy updating

Key Themes for B2B B2B will be much larger than B2C The timing is now Exchanges will introduce unprecedented market transparency B2B winners will establish platforms that link deeply with customers (e-hub) Many B2B business models will fail Buyers and Suppliers win

What Problems are We Solving? Commerce is fragmented by geography Most interactions between businesses are complex and labor- and information sensitive Supply chains are bloated with excess inventory because of the inability to see and plan for the right mixes and volume of products

A Question of Transparency Price transparency Availability transparency Supplier transparency Product transparency

Customer Feeding Frenzy: e-retailers vie for $185 billion Latest consumer e-commerce forecasts estimate at least a five-fold increase in sales from 1999 to 2003. Forrester Research issued the most detailed - and aggressive - outlook, predicting $185 billion in U.S. e-commerce sales by 2004.

Economic Spotlight: IT and Net Industries Drive U.S. Economy The U.S. Department of Commerce has compiled the latest analysis on the impact of the information technology and Internet industries in "The Emerging Digital Economy II." Available at www.ecommerce.gov, the report shows these industries contributed 29 percent of the nation's economic growth in 1998.

The Economic Impact of E-commerce Toy-giant Mattel will spend $50 million to launch an e-commerce venture that the company says will bring in $60 million this year, at gross margins greater than those of its traditional business. Sound good? A report from the Organization for Economic Cooperation and Development policy group has compiled over 150 pages of economic reasons why governments and businesses worldwide should pay attention to the ramifications of digital commerce.

The Economic Impact of E-commerce “The Economic and Social Impact of Electronic Commerce” report says business-to-business sales will help drive e-commerce revenues to $1 trillion in the 2003 to 2005 time frame. Companies like Mattel are taking advantage of the economic efficiencies of e-commerce: low-cost distribution, ordering and customer service, improved productivity and tighter inventory control. The OECD says the Net economy will result in lower prices for consumers, better information access and increased competitiveness of small and midsize businesses. It will also pave the way for a true global trading community.

The Economic Impact of E-commerce Equal access to e-commerce benefits is critical to the Internet Economy. Rich folks are more likely to have Internet access than poor folks in every country studied by the OECD. The report warns of a continuing worldwide shortage of skilled technology professionals. But an OECD analysis shows that, in the U.S. at least, traditional retail and information workers will have less to fear from a digital marketplace than their European counterparts.

B-to-B Forecasts

B-to-B Forecasts But Gartner’s corporate focus is understandable, given the way b-to-b conversion happens. “B-to-b gets adopted in chunks,” says Knight. “You’ve got entire companies, entire supply chains adopting e-commerce. It’s like a snowball effect.” Despite methodological and definitional variations, everyone agrees b-to-b will be big: in the neighborhood of $2 trillion in the U.S. by 2003, up from approximately $100 billion in 1999.

Behind the Numbers: The Mystery of B-to-B Forecasts Revealed One of the segments expected to grow the fastest is “e-marketplaces,” third parties that bring together multiple buyers and sellers online. According to Gartner, there were about 30 e-marketplaces in January 1999 and 300 by December. Forrester Research predicts that by 2004 more than half of all online b-to-b trade will be marketplace-driven.

Online Population Spotlight: Net Businesses Go Back to College Every year, marketers spend millions of dollars targeting college students just entering their prime as consumers. Now dozens of Net firms want in on the act. Source: Student Monitor Source: Cyber Dialogue

Geographic Market Fragmentation S B S B S S B B S S B B B S B S Premier buyer S Geography 1 B B S S Geography 3 B Premier seller B S Geography 2 Source: Morgan Stanley Dean Witter Internet Research

Enhanced Buyer and Seller Discovery Source: Morgan Stanley Dean Witter Internet Research

The Implications Strong competitors become dominant in efficient markets Weaker competitors get weaker Intermediaries at risk Suppliers become more specialized Buyers initiate/terminate relationships more easily Uniform prices

Time is Right for B2B Infrastructure ready Board room acceptance Speed and simplicity Lure of cost savings and efficiency Early adopters common Year of evaluation behind us Buyers are getting equity Vendors are pushing the next thing Well financed start ups and a good economy

B2B - Past, Present, and Future Phase 1 - Batch EDI Phase 2 - Basic E-Commerce Phase 3 - Communities of commerce Phase 4 - Collaborative commerce

Business-to-Consumer Interactions and transactions between a company and its consumers Focus is on selling goods and services and marketing to the consumer Dell, Amazon.com, eBay

Traditional vs Direct Selling Chain Manufacturer Distributor Supplier Reseller Wholesaler Customer Supplier Manufacturer Distributor Wholesaler Reseller Customer

Business Models

Introduction to Business Segments Consumer Retail businesses selling physical goods to an individual end consumer Business-to-Business cataloging businesses with online catalogs selling products to other businesses Information commerce businesses distributing digital goods

Segment Granularity, Market Size, and Timing Segmentation because of focus concentrating on exactly those elements that are essential to the application or market not diverting effort towards those elements that are either not needed or not appreciated by the customer

Segment Granularity, Market Size, and Timing Difficult to get right too broad => development resources may not stretch across all necessary features too narrow => market may not be large enough to support the business

Segment Similarities and Differences All have the need to attract customers, present products, assemble orders, do transactions, accomplish fulfillment, and deliver customer service Retail segment has more need for merchandising capability

Segment Similarities and Differences B2B have a greater need for payment by purchase order and for approval workflow Information commerce has a great need for online fulfillment

Consumer Retail - Value Proposition Ability to reach a global market Reduced marketing and selling expenses Increased efficiency of operations Ability to target consumers more precisely Ability to convey more accurate product and availability information

Consumer Retail - System Functionality Small shop static catalog and simple requirements Medium sized direct marketing product database and display templates Large Retailer Enterprise Resource Planning (ERP)

Attract - Advertising and Marketing banners on popular sites e-mail newsletters listings on widely used search engines Expense for the retailer Revenue to a vendor in the information commerce segment

Attract - Advertising and Marketing Coupons internet-based digital coupons may directly link to a transaction service Sales Promotions Frequent buyer programs

Attract - Advertising and Marketing One-to-One marketing Internet removes geographical basis for convenience price is always a difficult basis for competition leaves quality of service knowing a lot about the customer helps provide high quality service

Interact - Content Registration with Internet search engines Printed hypertext links on traditional menus, catalogs, and advertising Internet advertising on popular or related sites

Act - Order Processing Shopping cart or order aggregation function logical DB ot items considered for purchase Order validation validation based on business rules Application of coupons or other discounts affinity programs and quantity discounts

Act - Order Processing Cross selling offer buyer additional merchandise based on contents of shopping cart Calculation of sales and other taxes complex rule sets involving tax classification of product, location and tax status of buyer and seller Calculation of shipping and delivery charges bundled into price or extra and different forms

Act - Order Processing Presentation of the rolled-up order to the buyer reduces downstream issues customer service return dispute handling

Act - Order Processing Electronic cash Microtransactions and tokens low transaction cost Microtransactions and tokens fractions of a penny transactions Transaction Aggregation charging multiple events by the batch taxi meter or charge up meter accumulates usage charges parking meter or pay down buyer prepays a lump sum

Act - Fulfillment Traditional channels for physical goods On line for information commerce Downloading charge for the download itself appropriate for small downloads (unlikely to fail) charge for access rights to the download area access for a reasonable amount of time to do all the downloads

Act - Fulfillment Subscriptions; ongoing access charge for a license key delivering the key and content separately may be difficult planning for download failures Subscriptions; ongoing access Push Content; actively delivered by the content service

React - Customer Service Key issues are the same I didn’t buy that I didn’t receive the delivery (or broken) I didn’t like what I received I was charged the wrong amount With E-Commerce technology ensures that “I didn’t receive the delivery” is rare

Copy Protection and Rights Management Digital content can be copied Don’t worry about it Make copying very difficult container technology or license keys Make tracing the thief easy register each copy (fingerprint or watermark) Make paying for copies easy honest customers will use it

Electronic Data Interchange

EDI Inter-organizational exchange business documents standardized electrical form directly between computer applications purchase orders invoices material releases easy and inexpensive and structured

Industries that use EDI Automotive Retail Chemical Electronics Petroleum Metals Paper and Office products Still a relatively small percentage (about 100,000 companies)

Key Aspects of EDI Utilization of an electronic transmission medium (VAN) Use of structured formatted messages Relatively fast delivery of electronic documents (hours or minutes) Direct communication between applications (rather than just systems)

EDI costs Reaching a legal agreement (lawyers!) Building and installing the EDI system Modifying and interfacing with the existing computer system Obtaining network services Testing and installation Reengineering of internal processes Training

EDI Costs Rate-of return analysis should be done Cost shifting # transactions to amortize the cost effectively turnkey systems payment about 36 months Cost shifting dominant purchaser better economies of scale smaller companies have higher transaction cost Open architectures reducing cost

System Approach Single dedicated PC Group of computer performing many related functions Individual modems or modem pool Server as the interface to outside other computers for business applications dialup with a ISDN or dedicated link

Layered Architecture of EDI EDI semantic layer Application level services EDI Standard layer EDIFACT business form standards ANSI X12 business form standards EDI transport layer Electronic mail X.435, MIME Point to Point FTP, Telnet WWW HTTP Physical layer Dial up lines, Internet

Information flow without EDI Buyer Seller Finance department Purchase request initiated in the organization Finance department Bill Payment Purchase department Paper based mailroom Paper based mailroom Sales department Order delivery Order confirm Inventory and warehousing Receiving department Shipping department Manufacturing department Product delivery

Information flow with EDI Buyer Seller Finance department Purchase request initiated in the organization Finance department Billing details Payment details Purchase order delivery Purchase department EDI capable computer EDI capable computer Sales department Automated order confirmation Inventory and warehousing Receiving department Shipping department Manufacturing department Product delivery

EDI Process Network Vendor Buyer receive send send ack receive ack

EDI software Application software Message translator Routing manager Communication handler Shrink wrapped software available that provides many EDI functions

Communication approach Dial up is entry level Companies internal networks limit who you can interact with (VAN) Lots of competition between companies Internet is an appealing alternative

Open EDI Using the internet Cost of transferring messages is cheaper on the internet More cost effective movement of large files supplement purchase orders with product descriptions, graphics, video clips, etc

EDI across the Internet FTP login ID and password required for all trading partners directory names and files name agreement E-mail more secure less administration may not be able to handle large documents SMTP treats EDI as printable text (use MIME)

Challenges Internet security use encryption and digital signatures Not all VANs have connection to the internet may not have staff/expertise to switch MIME formatted EDI headers cannot be interpreted by VANs SMTP only supports negative delivery notifications use functional acknowledgment transaction

Network Architecture

On-Line Services Internet Service Providers vBNS Backbone Internet Society Internet Registry Regional Network Internet Registrar

Regional Network Modem Modem Router Satellite link Internet Provider Network Access Point Regional Network T3 line Router Backbone Router Network Access Point Ethernet Network T1 line

Communications Network Architectures THE OPEN SYSTEM INTERCONNECTION (OSI) MODEL Network User Network User Node B Logical Flow Node A Application Layer Transaction Services Provides application services, such as distributed database access and document interchange, to network users Transaction Services Presentation Layer Presentation Services Formats data for different presentation media and coordinates resource sharing Presentation Services Session Layer Data Flow Control Synchronizes flow between end-points, correlates exchanges and group related data into indivisible units Data Flow Control Transport Layer Transmission Control Paces data exchange to match end-point processing capacity and Enciphers user data, if needed security Transmission Control Network Layer Path Control Routes data in “packets” between source and destination and controls traffic and congestion in the network Path Control Data Link Layer Data Link Control Transmits data reliably between adjacent nodes all along any route Data Link Control Physical Layer Physical Control Connects adjacent nodes physically and electrically Physical Control Physical Flow

ISP Service Categories Web Hosting Services Security Services Dial-up Internet Access Managed Router Services Wholesale transit Services Dedicated Internet Access Colocation Provider VPN Services

Basic Network Regardless of the size of the ISP network, basic components are the same access devices data forwarding network elements (routers) information servers

ISP Size Small ISPs Larger ISPs modem pools (access concentrator) 24 modems connected to a local exchange carrier (LEC) via a T1 or primary rate ISDN Larger ISPs add more Points of Presence (POP) increase density of current POP POP is a location where the service provider is allowed to install equipment may be owned by somebody else

Internet Components Regional Point of Presence Major Point of Presence Residential Subscriber Backbone Modem Pool Router Routers Data Backbone

Routers Hardware and/or software that determines the next network point to forward a packet of data Connected to at least two network pathways Determines which pathway to route each information packet based on understanding of the state of the networks

Current Internet Network Architecture Very High Speed Backbone (operated by MCI) Backbone Network Access Provider Washington (MFS) California (PacBell) Chicago (Ameritech) New York (Sprint) Internet Access Provider Sprint MCI AT&T AOL UUNet PSI Local Access Provider Local Providers Local Providers Local Providers Local Providers Local Providers Local Providers End users Home Customers Small Bsinesses Large Businesses Government

Internet Topology Home Users dial into a local access provider using a PC modem use twisted pair existing telephone lines relatively slow businesses may choose faster access ISDN (Integrated Digital Systems Network) T-1 lines (1.544 Mbps) T-3 lines (45 Mbps)

Internet Topology All lines routed to a local access provider users switched through the direct connect access provider to the closest network access point (NAP) These access providers have proprietary, high-speed nationwide communication networks these are the local access points also called Points of Presence (POP) allow access to Internet with phone line

Internet Topology POPs necessary to reduce toll charges Established in major cities (local call for users) Modem pools and network interfaces convert analog dial-up signals from user into digital for more efficient transport to the backbone POPs connected by high speed telephone circuits to central hubs Hubs are connected to high-capacity network backbone physically connected to the Internet at geographically dispersed access points

Hardware in a POP Server Platform Networking Infrastructure powerful system for multiple users (Sun Workstation) Networking Infrastructure routers, terminal servers, switches provides POP to the internet Leased telecommunication lines from a local telephone company

Hardware in a POP Modems batch of modems to allow users to access the IAP racks of single or digital modems

Structure of a Point of Presence National Independent Backbone Internet T3 T3 ATM Switch T1 connections to customers Fast ethernet T1 56K connections to customers 28.8 Kbps or ISDN connections ISDN terminal server Distribution router Analog modems Terminal Server Inside a typical point of presence USENET server 9.6, 14.4, 28.8 Kbps

Dial up Access Connectivity Residential Subscriber Public Switched Telephone Network ISP Point of Presence (POP) Modem Internet Backbone Modem Router Voice Switch

Dial up Access POP Major Point of Presence Regional Point of Presences Modem Router Web Cache Major Point of Presence Residential Subscriber Backbone Regional Point of Presences Router Voice Switch Web Cache Router Public Switched Telephone Network Residential Subscriber Modem Router Web Cache Backbone

ISP dial up POPS are similar Access concentrator device that connects several modems into a single chassis Access concentrator connected to a colocated router across a LAN within the POP (ethernet hub) Router connected through telecom carrier to the ISPs IP transit provider (or upstream POP)

Digital Subscriber Access xDSL asymmetric (most common) symmetric very high speed Typical deployment 1.5 Mbs from ISP to customer 128Kbs back channel Similar to dial up connectivity with modem or NIC DSL modems connect to PC with ethernet

Digital Subscriber Line Access Multiplexer Modem ISP Point of Presence DSL Access Multiplexer Modem Router Residential Subscriber Internet Modem Voice Switch Residential Subscriber

Network Infrastructure for Electronic Commerce The Internet Architecture World Wide Web Concept and Architecture Protocol Gateway interfaces Web extensions Intranet Extranet

Information Superhighway Infrastructure I-way—the network infrastructure for electronic commerce Network Access Equipment Global Information Distribution Networks Local On-ramps Telecom-based infrastructure Cable TV-based infrastructure Consumer/ business premises equipment Backbone communications and satellite networks Wireless infrastructure Commercial on-line infrastructure

Internet Access Providers Telco companies—long distance telephone companies who traditionally focus on large business users and are now moving into consumer access market (e.g. AT&T, MCI, Sprint) Cable companies—access providers for home users via cable modems. May bundle Internet with other services (e.g. Time Warner, TCI)

Internet Access Providers Online companies—companies that package a range of information and Internet access for a monthly fee via local telephone number (e.g. America Online, CompuServe, Microsoft Network) National independents—for-profit entities that offer connectivity services nationwide or internationally

Internet Access Providers Targets business users and other smaller providers who do not have resources to provide widespread coverage (e.g. PSI, UUNET) Regional—nonprofit university affiliated enterprises that forming strategic alliances with larger players (e.g. SURAnet, NEARnet).

Internet Access Providers Local service providers—small businesses operate in one physical location and offer services within a single metropolitan area.

Internet Architectures

ISP Service Categories Web Hosting Services Security Services Dial-up Internet Access Managed Router Services Wholesale transit Services Dedicated Internet Access Colocation Provider VPN Services

Basic Network Regardless of the size of the ISP network, basic components are the same access devices data forwarding network elements (routers) information servers

ISP Size Small ISPs Larger ISPs modem pools (access concentrator) 24 modems connected to a local exchange carrier (LEC) via a T1 or primary rate ISDN Larger ISPs add more Points of Presence (POP) increase density of current POP POP is a location where the service provider is allowed to install equipment may be owned by somebody else

Internet Components Regional Point of Presence Major Point of Presence Residential Subscriber Backbone Modem Pool Router Routers Data Backbone

Dial up Access Connectivity Residential Subscriber Public Switched Telephone Network ISP Point of Presence (POP) Modem Internet Backbone Modem Router Voice Switch

Dial up Access POP Major Point of Presence Regional Point of Presences Modem Router Web Cache Major Point of Presence Residential Subscriber Backbone Regional Point of Presences Router Voice Switch Web Cache Router Public Switched Telephone Network Residential Subscriber Modem Router Web Cache Backbone

ISP dial up POPS are similar Access concentrator device that connects several modems into a single chassis Access concentrator connected to a colocated router across a LAN within the POP (ethernet hub) Router connected through telecom carrier to the ISPs IP transit provider (or upstream POP)

Digital Subscriber Access xDSL asymmetric (most common) symmetric very high speed Typical deployment 1.5 Mbs from ISP to customer 128Kbs back channel Similar to dial up connectivity with modem or NIC DSL modems connect to PC with ethernet

Digital Subscriber Line Access Multiplexer Modem ISP Point of Presence DSL Access Multiplexer Modem Router Residential Subscriber Internet Modem Voice Switch Residential Subscriber

Common Internet Access Methods Type of Internet Access Protocol Speed Cost Dial-up(shell account): Terminal 9.6, 14.4 $6-$20 / month, Easy and inexpensive, but Emulation Kbps unlimited usage cannot use Netscape. Dial-up IP: Full access to SLIP, PPP 14.4 Kbps $20 / month for 20 Internet, but more complex to 28.8 Kbps hours, $1-$2 / hour configure and set up thereafter Digital dial-up (ISDN): PPP 64, 128 Kpbs $30-$300 / month Not widely available, and has + installation problems with procurement 1 cent/minute and installation. Leased line: High-speed IP 56 Kbps $2500 dedicated link, but can be 1.544 Mbps $10K+$1500 / expensive if not used (T1) month frequently

The Web Enterprise Extranet Enterprise Intranet Internet Suppliers Distributors Logistics Provider Enterprise Knowledge Management Internal Communication Project Management Banks Intranet Internet Electronic Storefront Business Intelligence Customer Services Information Dissemination

Components of the Web Databases Web Browser TCP/IP based network (HTTP) CGI Content Web Clients Web Servers (web pages) Software applications 1. Browser establishes connection with server. 2. Browser issues request to server. 3. Server sends a response (page or graphics) 4. Both browser and server disconnect and the transaction ends. Common Gateway Interface (CGI) CGI defines how external applications can interact with Web servers HTML describes the contents of each Web page

Worldwide Web (WWW) The most popular Internet service (since 1993) WWW documents are linked to other documents by means of a technology called “Hypertext” The Web essentially contains an unlimited number of documents using a variety of media. When browsing Web resources, you decide how to navigate through the documents.

Worldwide Web (WWW) Web functions: view multimedia documents, download files, e-mail, discussion groups, run programs interactively, buy and sell goods and services. Middleware that operates on top of the Internet to support a community of users and applications

Worldwide Web (WWW) WWW makes hypermedia available on the Internet in what has evolved into a global information system. Web users can access corporate information by using Web gateways.

The World Wide Web (WWW) Web access to non-Web resources is provided through Web gateways Web access to relational databases is provided through “relational gateways” that serve as translators and mediators between Web browsers and relational database managers.

The World Wide Web Organizations can standardize on Web browsers for end-user access to all applications. The same Web interface can be used for applications that cross company, industry and country boundaries. Java is a programming language designed to work on the Web. Its application components run on the Web browser site, hence implementing the first-tier C/S applications.

Conceptual View of WWW UNIX Macintosh PC Web Browser (X Mosaic) (Netscape) Web Browser (Microsoft) HTTP HTTP Web search tools HTTP URL://http//seas.smu.edu/faculty.html Web Site www.shoes.com Web server (program) HTML documents Gateway for Database Access Web Site cs.um.edu Web server (program) HTML documents (Faculty.html, courses.html) databases

Why is the Web appealing? 1. All Web applications and technologies are standards-based => eliminate the need to port to multiple platforms to reach new markets 2. Web technologies are client/middleware/server applications =>users can readily utilize distributed computing resources

Why is the Web appealing? =>minimize need for end users to frequently upgrade existing hardware, OS or network infrastructures 3. New Web-based applications are maturing quickly =>Web technology may replace functionality of many current desktop and platform-centric applications of today.

Key Concepts of the WWW Global hypertext publishing—a seamless world in which all online information are accessed and retrieved in a consistent and simple way. Universal readership—a universal user interface can be used to read a variety of documents.

Key Concepts of the WWW Client/server interaction; Web can grow without any centralized control Web provides a way to interconnect computers running different operating systems and display information created in different media formats.

Protocol Greek; protocollon (leaf of paper glued to a manuscript) is a special set of rules for communicating Exist at several levels in a telecommunications connection Often describe an industry or international standard

Protocols Protocol stacks—a set of rules for inter-computer communication that has been agreed upon and implemented by many vendors, users and standard bodies. Two architectures: Open System Interconnection (OSI) and Transmission Control Protocol (TCP).

Protocols OSI TCP Application Layer Application or process Layer Presentation Layer TCP Session Layer Transport Layer Hot-to-host transport Layer Network Layer Internetwork (IP) Data Link Layer Network Interface Physical Layer Physical Layer

Encyphered or compressed OSI Protocol Stack Application Layer Application messages Presentation Layer Encyphered or compressed Session Layer Session messages Transport Layer Multiple packets Network Layer Packets Data Link Layer Frames Physical Layer Bits

TCP/IP TCP; uses a set of rules for exchanging messages with other internet points at the information packet level IP; uses a set of rules to send and receive messages at the Internet address level Others HTTP FTP

TCP/IP Basic communication language or protocol of the Internet Also used for intranets and extranets Setup with direct access to the Internet requires copy of TCP/IP program Two layers TCP; manages the assembling of a message or file into smaller packets that are transmitted over the Internet

TCP/IP Uses the client/server model of communication IP; handles the address part of each packet so that it gets to the right destination gateway computers on the network checks address to see where to forward the message packets re-assembled on the other end Uses the client/server model of communication

TCP/IP Communication is primarily point to point Connectionless freed network paths

TCP/IP Upper layer protocols often ties to TCP/IP as a suite HTTP FTP SMTP

TCP Protocol Stack FTP HTTP TELNET SNMP MBONE TCP UDP IP (ICMP, IGMP) Internet Addressing Physical layer Physical wiring

TCP/IP Sender Receiver 01100101 10001101 11011000 01010111 01100101 126.119.6.4 IP packets 126.119.6.4 Checksum Packet order Destination address Sender address Amount of time before discarding 126.119.6.4

WWW Middleware Web sites: provide the content that is accessed by Web users. Usually managed by content providers. Web server: a program (a server process) that receives calls from Web clients and retrieves Web pages and/or receives information from gateways.

WWW Middleware Web browsers: The graphical user interfaces that clients use to wander through the Web sites. Uniform Resource Locator (URL): A string of characters that uniquely identifies a resource. Used to locate resources in WWW.

WWW Middleware http://seas.smu.edu/faculty.html HTTP request initiated Name of machine running the Web server Name of the file on the machine cs.um.edu

WWW Middleware Hypertext Markup Language (HTML): a language that tags the text files for display at Web browsers Through HTML, users can flip through Web documents in a manner similar to flipping through a book or catalog. Hyperlinks: hypertext links that provide a path from one document to another. Hypertext Transfer Protocol (HTTP): application-level protocol designed for Web users establishes connection with the Web server specified in the URL, retrieves the document and closes the connection. Web navigation and search services: search engines that search and catalog the documents on the Web. Gateways to non-Web resources: applications that bridge the gap between Web browsers and corporate applications and databases.

Generic Web Gateway Interfaces Web Browsers HTTP Web Content (HTML Pages) Web Site Web Server Web Gateway Non-Web Content Web gateways bridge the gap between Web browsers and the corporate applications and databases. Types of Web gateways: Dedicated relational database gateway Common Gateway Interface (CGI) Java-based gateway

A Dedicated Relational Relational Database Manager Standalone Server A Dedicated Relational Database Gateway A specialized standalone server can be developed to behave as a gateway. Every call received by the server performs a gateway function: 1) Dedicated DB gateway receive SQL calls from a Web browser. 2) Sends SQL statements to target databases. 3) Receives results of SQL query. 4) Build HTML pages from results. 5) Send results back to Web browsers Web Browsers Response in HTML Request 5 1 Web Site Web Server 4 1 SQL Gateway 3 2 Relational Database Manager

CGI Gateways CGI gateway is a program that resides on the Web server The program can be a script (e.g. Perl script) or an executable program (e.g. a C++ program) Hyperlinks to this program are included in HTML documents When the user clinks on the hyperlink, The gateway URL is passed to the Web server which locates the program in the /cgi-bin/ directory and executes it Results sent back to the Web browser.

CGI Gateways Web Browsers Results Query Web Content (HTML Pages) Web Site Web Server CGI Gateway CGI Gateway Application Single Step Two Step E.g. DBMS

CGI Gateways HTML Web page CGI program Web Server CGI program (1) User enters information CGI program (2) Sends message to CGI program Web Browser Web Server 3) Process message (May call other programs) CGI program Application (5) User receives reply (4) Construct reply to user

Common Gateway Interface Generic interface between serve and gateway programs. Specifies how data are sent to and returned from gateway programs. Sending: environment variables e.g. REMOTE_ADDR, QUERY_STRING, REMOTE_HOST etc. data from clients (from standard input)

Common Gateway Interface Returning: Results that the server can process I.e. A HTML Web page with in HTML format. Server displays this Web page on the Web browser, which the user reads.

CGI Program Construct Directory where Perl is located #!/usr/bin/perl #program.pl -- name of program <Read input from client> Process data : print “Content-type: text/html\n\n”; <HTML Web page codes> May invoke another program to break down the input string into meaningful attributes and values Generate a reply HTML Web page

Java-Based Gateway Web Browser (Java Compliant) Gateway distributes code of the target application and sends it to the Web client where it executes. Access to remote application and databases can be invoked indirectly from the browser. Example: Java applet asks the user to query and sends it to a remote application or database. Appli- cations Java Applets Java Applets Request Web Site Web Server Java Powered Pages

Java and Java Applets Java is an object-oriented programming language similar to C++ developed by Sun Microsystem. Java supports user interactions with Web pages. Java applets are small Java programs embedded in Web pages

Java and Java Applets These Java Web pages (along with Java applets) are downloaded to the Web client and make the Web browsers a powerful tool by enabling user interactions. A Java application is a complete standalone application that uses text input and output

Java and Java Applets Java applets are not standalone applications and run as part of a Java-enabled browser (e.g. Hot Java). Clients need a Java-enabled browser to run Java-powered pages. Examples: HotJava, Netscape 2.0 and higher

Java Characteristics Simplicity Portable Object Orientation Distributed Robust Architectural Neutral Portable Interpreted High performance Multithreaded Dynamic Advantages: Network traffic reduction -- Java applets execute on the client side and thus do not suffer from the issues of network traffic between the Web client and Web server. Plug-and-play Java applets -- Java applets once built can run on many machines. They also have access to a wide range of libraries.

Downloading and running Java applets The Java browser load process consists of the following steps: User selects and HTML page. Browser locates the page and starts loading it. While loading, it starts to format text. It loads graphics if indicated by IMG or FIG tags in HTML.

Downloading and running Java applets Java applets are indicated by an APPLET tag Example <APPLET CODE=myapplet.class WIDTH=100 HEIGHT=100> </APPLET>

Downloading and running Java applets Browser loads the indicated class and other needed classes. Java-”enabled” browsers also keep local classes that may be used by the applets. After the applet has been loaded, the browser asks it to initialize itself (init() method) and draw a display area that is used for input/output.

Multimedia Web Extensions Virtual Reality Modeling Language (VRML) An object-oriented 3-D protocol that enables the creation of interactive 3-D environments on the Internet. Applications: virtual reality applications like molecular modeling, flight simulation, computer-aided product design

Multimedia Web Extensions RealAudio Streaming audio—sound files are played as they are being downloaded. Applications: live and rebroadcast music and audio Streaming video—towards video online? Internet/Web-based telephony E.g. Cool Talk—communication across the Internet with full duplex sound. Applications: cheap phone calls, shopping, customer service over WWW, interactive games.

Communications Network Architectures Communications network architectures. The OSI model is recognized as an international standard. IBM’s SNA is the leading network architecture for mainframe-based telecommunications networks. THE OPEN SYSTEM INTERCONNECTION (OSI) MODEL Network User Transaction Services Physical Control Data Link Path Transmission Data Flow Presentation Network User Transaction Services Physical Control Data Link Path Transmission Data Flow Presentation Node B Logical Flow Node A Application Layer Provides application services, such as distributed database access and document interchange, to network users Presentation Layer Formats data for different presentation media and coordinates resource sharing Session Layer Synchronizes flow between end-points, correlates exchanges and group related data into indivisible units Transport Layer Paces data exchange to match end-point processing capacity and Enciphers user data, if needed security Network Layer Routes data in “packets” between source and destination and controls traffic and congestion in the network Data Link Layer Transmits data reliably between adjacent nodes all along any route Physical Layer Connects adjacent nodes physically and electrically Physical Flow

E-Commerce Architectures

Electronic Commerce Architecture Client Browser WWW Server Functions 3rd Party Service Local or company specific data Information Retrieval Digital library of document/ data servers Mosaic/WWW browser Data and transaction management Third party information processing tools/services Browser extensions Secure messaging Electronic payment servers

A typical E-Commerce architecture Back End Web/Commerce Servers Web Clients Relational Database Document Management Payment System Imaging Proprietary ERP

Web Clients Web client (perspective of merchant) Browser (perspective of customer) Examples Mosaic Netscape Navigator Internet Explorer

Web Server/Commerce Server Web Clients Web/Commerce Servers Commerce Server S/W HTTP TCP/IP Web Server S/W

Web Server Software SITE SERVER COMMERCE SITE SERVER FRONT PAGE OPTION PACK/IIS SERVICE PACK 3 NT SERVER

Back End Servers Back End Web/Commerce Servers Web Clients

Back End Systems SQL DB2 Oracle ERP PeopleSoft SAP

Clustered Servers Web/Commerce Servers Web Clients Router Clustering Real-time Updates

Replicated Servers Web/Commerce Servers Web Clients Router Replication Scheduled Updates

Common Internet Access Methods Dial-up Easy and inexpensive Protocol; terminal emulation Speed; 9.6, 14.4 Kbps Dial-up IP full access to internet but more complex to configure and setup Protocol; SLIP, PPP Speed 14.4, 28.8 Kbps

Common Internet Access Methods Digital dial-up (ISDN) procurement and installation Protocol; PPP Speed; 64, 128 Kbps Leased Line high speed dedicated link Protocol; IP Speed; 56 Kbps, 1.544 Mbps (T1)

Point-to-Point Protocol Protocol for communication between two computers using a serial interface PC connected by phone line to a server ISP provides customer with PPP server responds to requests pass request on to internet forwards requested Internet responses back to you Uses IP Layer 2 (data link layer)

Point-to-Point Protocol Packages PC’s TCP/IP packets and forwards them to the server where they can then be put on the Internet Full duplex protocol twisted pair fiber optic satellite High Speed Data Link Control (HDLC) for packet encapsulation

Point-to-Point Protocol Can handle asynchronous as well as synchronous communication Can share the line with other users Generally preferred over SLIP (Serial Line Internet Protocol)

Another Configuration Front End Back-end databases Web/Commerce Servers Internet Software HTTP Protocols TCP/IP Router Internet Protocols TCP/IP Internal Credit Verification System External Web Clients Replication Internal Web Clients Firewall

A Typical Configuration Front End Back-end databases Web/Commerce Servers Internet Software HTTP Protocols TCP/IP Router Internet Protocols TCP/IP Internal Credit Verification System External Web Clients Internal Web Clients Firewall

Merchant Server - Physical View Financial Network Internet Buyer with Browser Catalog and order Database

Merchant Server - Logical View Catalog Data Order Data Credit Card Order Capture Forms Catalog Page Generation Static Content Web Server

Secure Electronic Transaction (SET) Architecture Merchant Server with SET module Interchange Network (mastercard, Visa, etc Internet SET payment gateway Buyer with browser and SET wallet

Open Market Commerce Architecture: Physical View Catalog servers with secure link Financial Network Internet Shared transaction server Buyer with browser

Shared Transaction Engine Internet Customer Data Order Data Payment Data Data Management Customer Management (Registration, Profiles) Order Capture (Order Form) Order Completion (Tax, shipping) Payment Processing (SET, Purchase Order) Fulfillment and Customer Service Catalog Server Catalog DB (Items, Pricing) Web Server Web Server Catalog Application SecureLink Internet Web Server

Open Buying on the Internet (OBI) Business Purchasing Process Browse Request Approve Fill Receive Pay

OBI Architecture Supplier Corporation Requisitioner Payment Authority Catalog Browse/Buy Order Status Query Requisitioner Order creation and approval Profile Information, Pending orders View/Update Payment Vehicle Authorization Clearance Payment Authority Buying Organization Payment Validation

OBI Transaction Flow Buyer home page (with list of suppliers) Seller catalog 1. Requisitioner selects supplier 2. Requisitioner browses catalog and orders Requisitioner Seller fulfillment systems 3. Catalog routes order to OBI server 5. Buyer approves requisitioners order 4. Seller sends OBI request to buyer 7. Seller routes order for fulfillment and payment Buyer OBI server (approvals, etc) Seller OBI server 6. Buyer sends complete OBI order to seller

Intranets and Extranets

The Web Enterprise Extranet Enterprise Intranet Internet Suppliers Distributors Logistics Provider Enterprise Knowledge Management Internal Communication Project Management Banks Intranet Internet Electronic Storefront Business Intelligence Customer Services Information Dissemination

Intranets A private network that is contained within an enterprise May consist of many interlinked local area networks and also use leased lines in the wide area network Typically includes connections through one or more gateway computers to the outside Internet

Intranets The main purpose of an intranet is to share company information and computing resources among employees An intranet can also be used to facilitate working in groups and for teleconferences.

Intranets An intranet uses TCP/IP, HTTP, and other Internet protocols and in general looks like a private version of the Internet Can send private messages through the public network using tunneling public network with special encryption/decryption and other security safeguards to connect one part of the intranet to another

Intranets Larger companies allow users within their intranet to access the public Internet through firewall servers that have the ability to screen messages in both directions so that company security is maintained When part of an intranet is made accessible to customers, partners, suppliers, or others outside the company, that part becomes part of an extranet

Internet vs. Intranet Internet A large collection of TCP/IP networks that are tied together through network interconnectivity such as routers and gateways. Computers on the public Internet have publicly known Internet Protocol (IP) addresses that are used to exchange information over the public Internet.

Internet vs. Intranet Intranet TCP/IP networks used by corporations for their own business, especially by exploiting Web technologies. Use the same technology as the public Internet. Any applications and services that are available on the public Internet are also available on the Intranets.

Intranet Benefits and Drawbacks Easy to publish internally Low cost since most organizations already have TCP/IP networks. Corporate users can easily access information on internal Web sites. Low maintenance and easy upgrading since information resides in only one place—the Web server Easy to scale the computing resources upwards or downwards.

Intranet Benefits and Drawbacks Easy software distribution through Web browsers. Drawbacks Collaborative applications for Intranets are not as powerful as those offered by traditional groupware. Short-term risk since Web programming technology is still relatively new. Less back-end integration since applications are separate unlike groupware.

Intranet Architecture Corporate Intranet Clients Legacy systems Public/ External WWW Users Intranet E-mail servers Firewall Databases Web servers

Extranet An extranet is a private network that uses the Internet protocols and the public telecommunication system to securely share part of a business's information or operations with suppliers, vendors, partners, customers, or other businesses An extranet can be viewed as part of a company's intranet that is extended to users outside the company

Extranet An intranet that is partially accessible to authorized outsiders Provides various levels of accessibility to outsiders intranet resides behind a firewall and is accessible only to people who are members of the same company or organization Must have a valid username and password, and your identity determines which parts of the extranet you can view.

Extranet It has also been described as a "state of mind" in which the Internet is perceived as a way to do business with other companies as well as to sell products to customers The same benefits that HTML, HTTP, SMTP, and other Internet technologies have brought to the Internet and to corporate intranets now seem designed to accelerate business between businesses

Extranet An extranet requires security and privacy. These require firewall server management, the issuance and use of digital certificates or similar means of user authentication, encryption of messages, and the use of virtual private networks (VPNs) that tunnel through the public network

Extranet Companies can use an extranet to: Exchange large volumes of data using Electronic Data Interchange (EDI) Share product catalogs exclusively with wholesalers or those "in the trade" Collaborate with other companies on joint development efforts Jointly develop and use training programs with other companies

Extranet Provide or access services provided by one company to a group of other companies, such as an online banking application managed by one company on behalf of affiliated banks Share news of common interest exclusively with partner companies

Extranet An extension of an enterprise’s Intranet to its business partners. Benefits: Leverage existing investment in technology since most companies already have their documents online and Internet access. Extranet applications developed to Internet standards are virtually guaranteed to work with Web browsers

Extranet Extranet applications can be customized to individual partners. Furthermore, the applications are accessible on a 24-hour basis, improving customer satisfaction. Issues: Security and access privileges Web site management and maintenance

Extranet Architecture Enterprise intranet Banks N N Suppliers N Intranet Extranet Internet Web browser Firewall servers Email IS Broadcast Contractors N N Manufacturer Discussion Search 3 rd party room engine N Distributor N cybermediary Product Purchasing catalog system extranet N Retailers Legend Product Info Purchasing Chat System rooms Direct-to- Virtual consumer community N N N Consumer Consumer Consumer

Internet, Intranet, Extranet Internet refers to outward-facing systems, with little or no connection to any other internal systems The Internet is the public, global network of networks which is based on the Internet Protocol (IP) and related standards Designed to provide a standard means of interconnecting networks (any system can communicate with any other system)

Internet, Intranet, Extranet It operates as a confederated network of networks (an "internet"), and offers universal accessibility

Internet, Intranet, Extranet Intranet refers to inward-facing or staff-facing systems A private application of the same internetworking technology, software, and applications within a private network, for use within an enterprise

Internet, Intranet, Extranet May be entirely disconnected from the public Internet usually linked to it and protected from unauthorized access by security firewall systems

Internet, Intranet, Extranet An intranet has two fundamental functions provide secure, customized access to relevant, up-to-date information found in transaction systems let users act on that information by managing how it flows through process systems

Internet, Intranet, Extranet An extranet is a use of Internet/intranet technology to serve an extended enterprise, including defined sets of customers or suppliers or other partners Typically behind a firewall, just as an intranet usually is Closed to the public (a "closed user group"), but is open to the selected partners, unlike a pure intranet

Internet, Intranet, Extranet More loosely, the term may apply to mixtures of open and closed networks. Extranet refers to the marriage of these two otherwise separate systems into a single, seamless system — a market-facing system.

IBM’s Ten Success Factors for E-Business 1. E-business is as much about business vision as technology 2. Key to a successful E-Business transition is making your E-Business priorities the same as your business priorities 3. When you move to E-Business, it pays to move quickly It pays to integrate E-Business with your core operations from the start

IBM’s Ten Success Factors for E-Business 5. Scalability, availability, and security are not optional 6. Customer knowledge is everything on the web 7. The key to transforming any major process is to identify all the subprocess 8. It pays to overbuild for traffic you do not expect

IBM’s Ten Success Factors for E-Business 9. A vital component of E-Business is a way to manage the performance of all your systems, networks, and applications - as a single enterprise 10. Plan for change - tomorrow will be different

So What is Distributed Computing?

Distributed Computing Computing is said to be "distributed" when the computer programming and data that computers work on are spread out over more than one computer, usually over a network Computing prior to low-cost computer power on the desktop, was organized in centralized "glass houses" (so-called because the computers were often shown to visitors through picture windows)

Distributed Computing Modern enterprises are using a mix of desktop workstations, local area network servers, regional servers, Web servers, and other servers

Distributed Computing A popular trend has been client- server computing which is simply the view that a client computer can provide certain capabilities for a user and request others from other computers that provide services for the clients (The Web's HTTP protocol is an example of this idea.)

Client/Server Computing

What is Client/Server Computing The client–server model consists of three parts: client - the active component that initiates a request server - the passive component that returns a service network - the media that enable the transmission of requests and services A request A request A service A service Server /Client Server Client

What are the Models of Client/Server Computing? The key is the leverage of computing power between Clients and the Server  How much work or how many functions are to be handled by the client versus its server

Major Components in Client/Server User Interface (I/O functions - Thin Client, WWW, Phone) User Interface (e.g., Browser, I/O routines) Functional Process (Business Rules) Functional Obj. (e.g., Stored procedures/Triggers) DBMS (for data access and retrievals, networking, services) Data Mgmt (e.g., DB2, Oracle, SQL/Server)

Major Models for Client/Server Three-Tier Model Client requests its service via some pre-compiled modules (COM) to interact with data access software on the server Agent (COM) Server Client Component Object Module (e.g., precompiled stored procedures)

3 Tier Client/Server “Desktop” - Compound Documents, Controls, Scripting C O M H T T P Mid-Tier - HTTP, Biz Objects, Active Server Pages, Scripting C O M SNA etc... CORBA Third-Tier - Databases, Legacy Data

Three-Tier Client/Server Model Data Mgmt Client DB Server User Interface (e.g., Browsers) Functions Function Server Communication Network

A New Trend in Object-oriented Client/Server - N-tier Model N-tier Architecture First tier Client Interface 2nd-tier Business COM Database Server Mail Server Gateway Server DNS Server 3rd-tier Business COM x-tier Business COM Back-end-tier System Server

Distributed Computing Most popular distributed object paradigms Common Object Request Broker Architecture (CORBA) Distributed Component Object Model (DCOM) Java/Remote Method Invocation (Java/RMI)

CORBA and ORBs

CORBA Common Object Request Broker Architecture Brokers requests for services from objects that may reside elsewhere on a network Provides location independence Provides vendor and language interoperability

CORBA Everything in the CORBA architecture depends on an Object Request Broker (ORB) acts as a central Object Bus over which each CORBA object interacts transparently with other CORBA objects located either locally or remotely

CORBA Since CORBA is just a specification, it can be used on diverse operating system platform mainframes UNIX boxes Windows machines handheld devices As long as there is an ORB implementation for that platform

CORBA Architecture Object Request Broker (ORB) is the most important component Object Services are the low-level services that must be available on all platforms in a distributed system (e.g., lifecycle)

CORBA Architecture Common Facilities are the commonly-found services in particular distributed systems (e.g., email, print queuing) Application Objects are the high-level applications themselves (e.g., spreadsheets, word processors, programmable controllers)

CORBA Architecture CORBA ORB CORBA Applications CORBA Facilities CORBA Domains CORBA ORB CORBA Services

Object Request Broker A CORBA Object Request Broker (ORB) is the middleware that establishes the client-server relationship between objects Using an ORB, a client object can invoke a method on a server object that can be on the same machine or across a network

Object Request Broker The ORB intercepts the call and finds an object that can implement the request, pass it the parameters, invoke its method, and return the results CORBA, like SQL, provides both static and dynamic interfaces to its services

Object Request Broker The client does not have to know the object's location, its programming language, its operating system, or any other system aspects that are not part of an object's interface Also, the client and server roles are dynamic: an object on the ORB can act as either client or server, depending on the occasion

Communicating via ORBs Local Host Java Interpreter or Browser Client Applet Remote Host Request Request Object Implementation ORB

Distributed Computing with CORBA The client application does not need to know whether the object resides on the same computer or on a remote computer elsewhere on the network The client application needs to know only two pieces of information the object's name how to use the object's interface

Distributed Computing with CORBA The ORB takes care of the details locating the object routing the request returning the result

Features and Benefits Each object encapsulates the details of its inner workings and presents a well-defined interface, reducing application complexity The CORBA approach also reduces development costs, because once an object is implemented and tested, it can be used over and over again

Features and Benefits CORBA's platform independence lets you run and invoke the object from any platform; you can run an object from the platform that makes the most sense for that object CORBA's language independence lets you reuse existing code and leverage your existing programming skills

Features and Benefits CORBA is based on an open, published specification Implemented on and supported by numerous hardware and operating system platforms CORBA Java objects are portable build objects on one platform and deploy them on any other supported platform

Features and Benefits Interoperability. CORBA objects are fully interoperable because they communicate using the Internet Inter-ORB Protocol (IIOP) Software bridges enable communications between CORBA objects and objects developed using Microsoft's DCOM technology

Features and Benefits Modularity. CORBA objects interact via interfaces developers can modify objects without breaking other parts of the application Changing an object's implementation does not affect other objects or applications because that object's interface stays the same

Features and Benefits Compatibility. CORBA protects your investment in existing systems You can encapsulate a legacy application, module, or entry point in a CORBA IDL wrapper that defines an interface to the legacy code Security. CORBA provides security features such as encryption, authentication, and authorization to protect data and to control user access to objects and their services

CORBA Environment Source: Netscape

CORBA in a Three Tier Architecture Source: Netscape

Example Parcel-tracking application Suppose an Internet user wants to track delivery of a package From a browser, the user enters a URL that points to the delivery company's Web server Source: Netscape

Example The server uses HTTP to send a Web page to the user that page contains an embedded Java applet, which is the client component of the parcel-tracking system So far, nothing is different from a traditional HTTP Web transaction

Example Next, the user enters a parcel-tracking number into the appropriate field in the Java applet Using the client-side ORB, the applet then generates and sends an IIOP message across the network, looking for a specifically-named server object that can obtain the status of the parcel

Example The ORB on the server with the appropriate parcel-tracking object picks up the message and invokes the object's status-finding method Through the server ORB, the object then generates another IIOP message looking for an object on a legacy system that contains all the parcel company's data

Example Upon obtaining the last request through its ORB, the mainframe containing the data-tracking object determines that status of the parcel from its database The mainframe returns an IIOP message with the information to the server object

Example The server then routes the information-again with IIOP and the ORBs-to the Java applet running on the client, which displays the results to the user

Example Source: Netscape

COM COM (Component Object Model) is Microsoft's framework for developing and supporting program component objects It is aimed at providing similar capabilities to those defined in CORBA

COM COM provides the underlying services of interface negotiation, life cycle management (determining when an object can be removed from a system), licensing, and event services (putting one object into service as the result of an event that has happened to another object) COM includes COM+, DCOM, and ActiveX interfaces and programming tools

COM Principles Rigorous Encapsulation Polymorphism Black box -- no leakage of implementation details All object manipulation through strict interfaces Polymorphism via multiple interfaces per class “Discoverable”: QueryInterface IUnknown IDispatch COM Object IRobot

COM Architecture Inprocess Local Remote Source: Microsoft COM run time Client Component Security provider RPC provider Security RPC Inprocess Protocol stack Local LPC Protocol stack DCOM network- protocol Remote Source: Microsoft

COM Runtime Architecture Flexible and extensible Pluggable Transports Client Machine Server Machine Component TCP, UDP COM Client Proxy SPX,IPX COM Runtime COM Runtime Net BUI HTTP “Falcon” Other Component Source: Microsoft

The COM Architecture A scalable programming model In the same process Fast, direct function calls Component Client Client Process Server Process On the same machine Fast, secure IPC Component COM Client Across machines Secure, reliable and flexible DCE-RPC based DCOM protocol Client Machine Server Machine Component DCE RPC COM COM Client Source: Microsoft

DCOM DCOM which is often called 'COM on the wire', supports remoting objects A DCOM server is a body of code that is capable of serving up objects of a particular type at runtime DCOM server components can be written in diverse programming languages like C++, Java, Object Pascal (Delphi), Visual Basic and even COBOL

DCOM As long as a platform supports COM services, DCOM can be used on that platform DCOM is now heavily used on the Windows platform

COM/DCOM Lets ActiveX components run anywhere Client Server Object running on client Remote object on any server COM COM Object running on client Source: Microsoft

COM and DCOM DCOM COM Client Source: Microsoft COM COM COM COM COM COM Sun Solaris (Sparc) 2.5 RC HP/UX COM COM Q3’97 Q4’97 Digital Unix 4.0 (Alpha) RC Digital Open VMS COM COM COM Client Q3’97 H1’98 DCOM IBM MVS 5.2.2 (OS390) Siemens Nixdorf SINIX COM COM Q1’98 H1’98 IBM OS/400 Linux 2.0 (Intel) BETA COM COM H1’98 Q4’97 IBM AIX SCO UnixWare COM COM H1’98 H1’98 Source: Microsoft

Architecture Overview Containers Office Binder Mosaic Internet Explorer Windows Shell HTML VRML Word Visio MicroGrafx ActiveX documents Internet Explorer MPEG VRML RealAudio HTML ActiveX controls Shockwave ODBC HTML VRML HTML VRML Visual Basic Script JavaScript REXX ActiveX scripting PERL Visual Basic Script URL resolution HTTP, FTP Hyperlinking History Favorites Code download and security Services JavaScript

COM+ COM+ is an extension of COM COM+ is both an object-oriented programming architecture and a set of operating system service It adds to COM a new set of system services for application components while they are running, such as notifying them of significant events or ensuring they are authorized to run

COM+ COM+ is intended to provide a model that makes it relatively easy to create business applications that work well with the Microsoft Transaction Server (MTS) in a Windows NT system

COM+ It is viewed as Microsoft's answer to the Sun Microsystems-IBM-Oracle approach known as Enterprise JavaBeans (EJB) Among the services provided by COM+ are: An event registry that allows components to publish the possibility of an event and other components to subscribe to be notified when the event takes place

COM+ The interception of designated system requests for the purpose of ensuring security The queueing of asynchronously received requests for a service

Technology Scenario COM+ COM MTS COM+ A caring, sharing COM+ Services: Events Security Load Balancing Queued Components In Memory Database Compensating Resource Manager Administration MTS MTS Services: Transactions Resource Pooling Security Administration COM+ A caring, sharing environment for your components COM The Model Tools Support Multi-Language Discovery (QI)