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In ter net, In tra nets , and Ex tranets. Chapter 3. Historic Stuff. Early Developments Packet Switching (data is broken up into small chunks and each is given information as to when they were sent and where they were going. They could then be reassembled at their destination)
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Internet, Intranets, andExtranets Chapter 3 ©2003 Pearson Education Canada Inc.
Historic Stuff • Early Developments • Packet Switching (data is broken up into small chunks and each is given information as to when they were sent and where they were going. They could then be reassembled at their destination) • Development of protocols (a set of transmission rules that both ends of the transmission understand) • TCP – Transmission Control Protocol – packet level transmission protocol • IP – Internet Address Level Protocol – every POP (point of presence) has an IP address • The above two protocols are generally referred to as the TCP/IP protocol ©2003 Pearson Education Canada Inc.
Internet TechnologyContinued • TCP/IP - Transmission Control Protocol/Internet Protocol - Every computer on the Internet must have the TCP/IP program installed to be able to talk to other computers • The basic protocol of the Internet • IP - is responsible for moving packet of data from node to node. IP forwards each packet based on a four byte destination address (the IP number). • TCP - is responsible for verifying the correct delivery of data from client to server. Data can be lost in the intermediate network. TCP adds support to detect errors or lost data and to trigger retransmission until the data is correctly and completely received. ©2003 Pearson Education Canada Inc.
Internet Technology Continued • HTTP - Hypertext Transfer Protocol - set of rules for exchanging files (text, graphics, sound, video) on the Web • HTTPS -Secure Hypertext Transfer Protocol - encrypts and decrypts transmissions on the Web. Uses Netscape’s Secure Socket Layer (SSL) <SSL works by using a private key to encrypt data that's transferred over the SSL connection. The protocol allows an SSL-enabled server to authenticate itself to an SSL-enabled client, allows the client to authenticate itself to the server, and allows both machines to establish an encrypted connection. > • HTML - – Hypertext Markup Language - a set of source codes <img src="peter.jpg" width="200" height="150">, for formatting Web pages • XML - Extensible Markup Language – extension of HTML which can describe the content in terms of what data is being included. • Set objDom = server.CreateObject("Microsoft.XMLDOM") objDom.preserveWhiteSpace = True blnFileExists = objDom.Load(strXMLFilePath & "\" & strFileName) • If blnFileExists = True Then ©2003 Pearson Education Canada Inc.
Metatags • A special HTML tag that allows a page designer to describe the web page and influence how the page is indexed by search engines. <meta name="keywords" content="flowers, flower, virtualflowers, virtual flowers, virtual flowers, 800, free, no tax, virtual bouquet, vir virtual florist, floral arrangements, flor, flores, flower arrangements floral, florals, gift, gifts, bouquet, bouquets, rose, roses, birthday, b anniversary, anniversaries, mother's day, flowers, flower, virtualflo ©2003 Pearson Education Canada Inc.
Internet Technology Continued • CGI - Common Gateway Interface - method under which a server passes a user request to an application and receives data for sending to the user (e.g. a request for data from a database program would be made through the CGI program) • Active Server Pages (ASP) - An alternative to CGI is Microsoft’s • Java - Programming Language for use in internet/distributed environments • Can create applets (small applications) that make web pages interactive • Browser needs a special “Plug-in” to run Java • // http://hostname.com/mywebapp/servlet/MyServlet/a/b;c=123?d=789 public static String getUrl(HttpServletRequest req) { String reqUrl = req.getRequestURL().toString(); String queryString = req.getQueryString(); // d=789 if (queryString != null) { reqUrl += "?"+queryString; } return reqUrl; } ©2003 Pearson Education Canada Inc.
URLhttp://www.webopedia.com/TERM/U/URL.html • URL - Abbreviation of Uniform Resource Locator, the global address of documents and other resources on the World Wide Web. The first part of the address indicates what protocol to use, and the second part specifies the IP address or the domain name where the resource is located. ©2003 Pearson Education Canada Inc.
DNS • 1) Short for Domain Name System (or Service or Server), an Internet service that translates domain names into IP addresses. Because domain names are alphabetic, they're easier to remember. The Internet however, is really based on IP addresses. Every time you use a domain name, therefore, a DNS service must translate the name into the corresponding IP address. For example, the domain name www.example.commight translate to 198.105.232.4. The DNS system is, in fact, its own network. If one DNS server doesn't know how to translate a particular domain name, it asks another one, and so on, until the correct IP address is returned ©2003 Pearson Education Canada Inc.
WWW Architecture Databases Client Client Server A B HTTP HTTP HTTP Content CGI TCP/IP TCP/IP TCP/IP Software Applications Internet Network ©2003 Pearson Education Canada Inc.
Definition of Intranet • Internal network that uses Internet technology • Looks like a private version of the Internet • Typically has connections to the Internet through Gateway Computers (protected by firewalls) ©2003 Pearson Education Canada Inc.
Definition of Extranet • Externalnetwork that uses Internet technology • Often uses public telecommunications system (telephone cables, satellites, microwave systems) • Often Includes (e.g. gives access to) outside users like suppliers, vendors, partners, customers • Unlike Internet it requires a login and password ©2003 Pearson Education Canada Inc.
Advantages of Intranets and Extranets • Consistent and reliable platforms • Platform (computer system- Apple, PC, main frame, etc.) independence • Consistent and friendly user interfaces • Familiar to users worldwide • Uses the same protocols as the Internet • Reduces certain business costs • Improves access to data for both employees and customers • Removes 9 to 5 access to information ©2003 Pearson Education Canada Inc.
Disadvantages of Intranets and Extranets • Security concerns (easy to hack) • Bandwidth (amount of traffic possible)/scalability (can bandwidth be increased to take more traffic?) • Measuring ROI (Return On Investment) e.g. It is difficult to measure the success of your investment which can be attributed to your Intranets and/or Extranets) • Constant change (Both software and hardware are constantly changing/improving and it is an expensive exercise keeping Intranets and Extranets up to date) ©2003 Pearson Education Canada Inc.
Uses of Intranets • Publish information to staff • policy manuals, newsletters, etc. • Individual department/employee Web pages • Gathering data - time reports, schedules, customer visits • Allows remote access to business ©2003 Pearson Education Canada Inc.
More Advanced Uses for Intranets • Interactive apps - polling for opinions • Training • Integration with corporate data • prices, product info and sales stats • accounting, asset tracking, etc. • Possibly for video conferencing ©2003 Pearson Education Canada Inc.
Uses of Extranets • Product catalogues • Take orders, sell goods • Handle enquiries • Integrate with suppliers • VMI (Vendor Managed Inventory) ©2003 Pearson Education Canada Inc.
Virtual Private Networksa secure and encrypted connection between two points across the Internet • Uses Internet infrastructure • Advantages of the net without the disadvantages • scalability, connectivity, reach, user friendliness, common protocols, etc • deals with security problems (possibly by using tunneling) Point A encryption Internet Point B decryption ©2003 Pearson Education Canada Inc.
Virtual Private Network (VPN) Technology • Tunneling ( data transmitted across the Internet contains an additional header that establishes its route through the Internet) • Encrypted transmissions • Uses an ISP (Internet Service Provider) for access (therefore cheaper to use) • VPN Software ©2003 Pearson Education Canada Inc.
e-Commerce Usage of VPNs • Creation of private networks on the Internet • Intranets and Extranets (can be cheaply run over great distances) • Solves infrastructure issues (since it is using structures already tested and in place) ©2003 Pearson Education Canada Inc.
Example of using e-tech in a business • FedEx – Discussion • More than 2.5 million customers are connected electronically with FedEx Express – FedEx’s Web site for its customer automation systems -- and about two-thirds of U.S. domestic transactions are processed electronically every business day. • FedEx Tracking Extranet • http://www.fedex.com/Tracking?cntry_code=us ©2003 Pearson Education Canada Inc.
The End ©2003 Pearson Education Canada Inc.