Unit Iv


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Unit Iv

  1. 1. Internetworking • Internetworking involves connecting two or more distinct computer networks or network segments via a common routing technology. The result is called an internetwork (often shortened to internet). • The most notable example of internetworking is the Internet (capitalized), a network of networks based on many underlying hardware technologies, but unified by an internetworking protocol standard, called the Internet Protocol Suite (TCP/IP).
  2. 2. • An internetwork is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. Internetworking refers to the industry, products, and procedures that meet the challenge of creating and administering internetworks. Figure 1-1 illustrates some different kinds of network technologies that can be interconnected by routers and other networking devices to create an internetwork.
  3. 3. Basics of Internetworking • Gives an illusion of a single (direct link) network • Built on a set of distributed heterogeneous networks • Abstraction typically supported by software
  4. 4. Internetwork properties • Supports heterogeneity: Hardware, OS, network type, and • topology independent • Scales to global connectivity
  5. 5. Internet Protocol (IP) • Network- level protocol for the Internet • Operates on all hosts and routers • Protocol stack has an “hourglass” shape
  6. 6. Protocols • Protocols are sets of rules that define how different parts of a network interact to allow devices to communicate with one another. They provide a ‘common language’ to allow different vendors’ computer equipment to communicate with each other. The different devices can use completely different software, provided that each device’s software can agree on the meaning of the data. Protocols can describe low-level details of machine-to-machine interfaces (like the order in which bits and bytes are sent across the wire) or high-level exchanges between allocation programs (the way in which two programs transfer a file across the Internet).
  7. 7. Internet Protocols • The Internet Protocol defines a connectionless data delivery service between networked devices. Packets of data are sent as datagrams across the network. Large packets may be broken into several datagrams which are each sent individually across the network. Each datagram carries its full destination address and control information.
  8. 8. • To route packets in an internetwork, IP uses a dynamic routing protocol called the Routing Information Protocol (RIP). Today RIP is the most commonly used Interior Gateway Protocol (IGP) in theInternet community. The primary function of RIP is to inform routers about other routers on the network.
  9. 9. Serial Line Internet Protocol (SLIP) • SLIP transmits IP packets over serial lines. If using SLIP, the network must use TCP/IP as its primary means of communication between resources. A SLIP connection only allows one communication application to be active at any one time.
  10. 10. Simple Mail Transport Protocol (SMTP) • SMTP transfers e-mail from one server to another across the network. • End users must use the Post Office Protocol (POP) to transfer the • messages to their machines.
  11. 11. File Transfer Protocol (FTP) • FTP provides a way to move files between computer systems. It is a widely used way of transferring files to and from the Internet and is relatively simple to operate.
  12. 12. WWW Structure • Clients use browser application to send URIs via HTTP to servers requesting a Web page • Web pages constructed using HTML (or other markup language) and consist of text, graphics, sounds plus embedded files • Servers (or caches) respond with requested Web page – Or with error message • Client’s browser renders Web page returned by server – Page is written using Hyper Text Markup Language (HTML) – Displaying text, graphics and sound in browser – Writing data as well • The entire system runs over standard networking protocols (TCP/IP, DNS,…)
  13. 13. HTTP Basics • Protocol for client/server communication – The heart of the Web – Very simple request/response protocol • Client sends request message, server replies with response message – Stateless – Relies on URI naming mechanism
  14. 14. WWW Pages and Browsing • A web browser is a software application which enables a user to display and interact with text, images, videos, music, games and other information typically located on a Web page at a website on the World Wide Web or a local area network. Text and images on a Web page can contain hyperlinks to other Web pages at the same or different website. Web browsers allow a user to quickly and easily access information provided on many Web pages at many websites by traversing these links. Web browsers format HTML information for display, so the appearance of a Web page may differ between browsers.
  15. 15. Security • When a computer connects to a network and begins communicating with others, it is taking a risk. Internet security involves the protection of a computers internet account and files from intrusion of an outside user. Basic security measures involve protection by well selected passwords, change of file permissions and back up of computers data.
  16. 16. • A network security policy is a generic document that outlines rules for computer network access, determines how policies are enforced and lays out some of the basic architecture of the company security/ network security environment. The document itself is usually several pages long and written by a committee. A security policy goes far beyond the simple idea of "keep the bad guys out". It's a very complex document, meant to govern data access, web-browsing habits, use of passwords and encryption, email attachments and more. It specifies these rules for individuals or groups of individuals throughout the company. • Security policy should keep the malicious users out and also exert control over potential risky users within your organization. The first step in creating a policy is to understand what information and services are available (and to which users), what the potential is for damage and whether any protection is already in place to prevent misuse.
  17. 17. • In addition, the security policy should dictate a hierarchy of access permissions; that is, grant users access only to what is necessary for the completion of their work. • While writing the security document can be a major undertaking, a good start can be achieved by using a template. National Institute for Standards and Technology provides a security- policy guideline. • The policies could be expressed as a set of instructions that could be understood by special purpose network hardware dedicated for securing the network.
  18. 18. E- Commerce • UK Government “E-Commerce is the exchange of information across electronic networks at any stage in the supply chain whether within an organisation , between businesses, between business & consumers, or between public and private sectors whether paid or unpaid” • Zwass (1998) “ E-Commerce is the sharing of business information , maintaining business relationships & conducting business transactions by means of telecommunications networks”
  19. 19. E-Business & E-Commerce • IBM’s Definition of E-Business – “The transformation of key business processes through the use of internet technologies” • R. Kalakota (1999) “E-Commerce is buying & selling activities over digital media” – E-Business – encompasses e-commerce & “includes the front & back-office applications that form the engine for modern business. Its not just about e- commerce transactions, it’s about redefining old business models with the aid of technology to maximise customer value”
  20. 20. Rules of E-Business • Rule 1 – Technology is no longer an afterthought in forming business strategy – It’s the actual cause & driver • Whilst computers didn’t fundamentally alter business foundations – the internet does. • Rule 2 - Ability to streamline, structure, influence and control the flow of information is more powerful & cost-effective than moving & manufacturing physical products • intangibles are becoming more valuable - branding, customer relationship, integration • Rule 3 – Inability to overthrow the dominant, outdated business design often leads to failure. • move to outsourcing & high levels of internal integration • Rule 4 – Goal of new business design is to create flexible outsourcing alliances between companies that not only off load costs but also make customers ecstatic. • Speed, Convenience, Personalisation, Price
  21. 21. • Rule 5 – e-Commerce is enabling companies to listen to their customers and become either the cheapest, the most familiar, or the best • Wal-Mart, McDonalds, Coca–Cola, Amex – What have you done for me ? • Rule 6 – Use technology to innovate, entertain, and enhance the entire transaction process from selection to receipt & service • Amazon,. • Rule 7 – Future e-business design models will increasingly use reconfigurable e-business community models to best meet customer’s needs. • Integrated customer centric business models – supporting complex business designs – IF, Cahoot, Amazon, E-Trade • Rule 8 – Management’s task is to align business strategies, processes and applications , fast, right and all at once – very difficult
  22. 22. Electronic commerce • To many people the term electronic commerce, – often shortened to e-commerce, is equivalent – to shopping on the web. • The term electronic business is sometimes used – to capture the broader notion of e-commerce. • In this course, we will use e-commerce in its – broadest sense. It encompasses both web – shopping and other business conducted – electronically.
  23. 23. Electronic commerce • Banks have used electronic funds transfers – (EFTs), also called wire transfers, for decades. • Businesses have been engaging in electronic – data interchange for years. EDI occurs when – one business transmits computer readable data – in a standard format to another business.
  24. 24. • We will define e-commerce as the use of electronic • data transmission to implement or enhance any • business activity. • Example (Figure 1-4): A buyer sends an electronic • purchase order to a seller. The seller then sends an • electronic invoice back to the buyer. • When used appropriately, electronic transmission • can save both time and money.
  25. 25. Impact of e-commerce • E-commerce is changing the way traditional • commerce is conducted: • Technology can help throughout the process – including promotion, searching, selecting, – negotiating, delivery, and support. • The value chain is being reconfigured.
  26. 26. Advantages of e-commerce • For the seller: • Increases sales/decreases cost • Makes promotion easier for smaller firms • Can be used to reach narrow market segments • For the buyer: • Makes it easier to obtain competitive bids • Provides a wider range of choices • Provides an easy way to customize the level of – detail in the information obtained
  27. 27. Advantages of e-commerce • In general: • Increases the speed and accuracy with which – businesses can exchange information • Electronic payments (tax refunds, paychecks, – etc.) cost less to issue and are more secure • Can make products and services available in – remote areas • Enables people to work from home, providing – scheduling flexibility
  28. 28. Advantages of e-commerce • Some business processes are not suited to – e-commerce, even with improvements in – technology • Many products and services require a critical – mass of potential buyers (e.g. online grocers) • Costs and returns on e-commerce can be – difficult to quantify and estimate • Cultural impediments: People are reluctant to – change in order to integrate new technology • The legal environment is uncertain: Courts and – legislators are trying to catch up
  29. 29. Disadvantages of e-commerce • Some business processes are not suited to – e-commerce, even with improvements in – technology • Many products and services require a critical – mass of potential buyers (e.g. online grocers) • Costs and returns on e-commerce can be – difficult to quantify and estimate • Cultural impediments: People are reluctant to – change in order to integrate new technology • The legal environment is uncertain: Courts and – legislators are trying to catch up
  30. 30. E-Commerce Market Place Electronic Commerce is part of an evolving approach to business that could eventually involve the application of Information & Communication Technology (ICT) to the Product and Distribution of goods and services on a global scale. Electronic Commerce can be used to support fully automated transactions, but, for immediate future at least, it also encompasses many partially automated transactions involving human and physical interfaces and intermediaries of various kinds.
  31. 31. Participating Groups in E-Commerce • Electronic Commerce can occur within and between three basic participant groups- – Business – Government – Individuals At present and by a large margin, most e- commerce occurs on a B-to_B level.
  32. 32. Economic Potential of E-Commerce • E-Commerce is the marriage between a rapidly evolving technical environments and an increasingly pervasive set of ideas as to how markets should function. • However markets involve complex interaction between specific business/ organizational factors and general economic, social and political factors. • At this point in time, Economic Potential of E- commerce can only be evaluated against a backdrop of rapid change on all of these fronts.
  33. 33. Forces behind E-Commerce • Internet Acceptance is the Driving Force Behind e-Commerce • Increased Awareness • Significant improvements in Infrastructure • Increased Competition among the organization and thus in search of the technologies and ways to take the edge over others. • Customer Oriented markets
  34. 34. E-Commerce Framework
  35. 35. E-Commerce Framework