1 / 38

Chapter 4: Networking and the Internet

Chapter 4: Networking and the Internet. Computer Science: An Overview Tenth Edition by J. Glenn Brookshear. Chapter 4: Networking and the Internet. 4.1 Network Fundamentals 4.2 The Internet 4.3 The World Wide Web. Network Classifications. Scope Local area network (LAN)

tyrone-munoz
Download Presentation

Chapter 4: Networking and the Internet

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 4:Networking and the Internet Computer Science: An OverviewTenth Edition by J. Glenn Brookshear

  2. Chapter 4: Networking and the Internet • 4.1 Network Fundamentals • 4.2 The Internet • 4.3 The World Wide Web

  3. Network Classifications • Scope • Local area network (LAN) • Metropolitan area (MAN) • Wide area network (WAN) • Ownership • Closed versus open  Internet is an open network • Topology (configuration-physical layout of network) • Bus (Ethernet) • Star (Wireless networks with central Access Point)

  4. Figure 4.1 Network topologies Access point (Server)

  5. Protocols • The set of rules by which activities are conducted • Example: Protocols which controls rights to transmit messages • CSMA/CD(Carrier Sense, Multiple Access with Collision Detection) • Used in Ethernet • Silent bus provides right to introduce new message • CSMA/CA(Carrier Sense, Multiple Access with Collision Avoidance) • Used in WiFi • Hidden terminal problem

  6. Figure 4.2 Communication over a bus network

  7. Figure 4.3The hidden terminal problem

  8. Connecting Networks • Repeater • Extends a network • Simply transmits messages with some form of amplification • Bridge: • Connects two compatible networks • Transmits message ony when that message is destined for a computer on the other side

  9. Connecting Networks • Switch: • A bridge with multiple connections • Connect several compatible networks • Minimizes traffic load • Repeater, bridge and switch are used to construct a single large network (same protocol) • Router: Connects two incompatible networks resulting in a network of networks called an internet

  10. Figure 4.4 Building a large bus network from smaller ones

  11. Figure 4.5Routers connecting two WiFi networks and an Ethernet network to form an internet Wi Fi = Wireless Fidelity

  12. Inter-process Communication • The communication between computers within a network • Methods of process communication • Client-server model • One server, many clients • Server must execute continuously • Client initiates communication • Peer-to-peer (P2P) model • Two processes communicating as equals • Peer processes can be short-lived

  13. Figure 4.6 The client/server model compared to the peer-to-peer model

  14. Distributed Systems • Systems with parts that run on different computers • eg. global information retrieval systems, companywide accounting and inventory systems, computer games. • Infrastructure can be provided by standardized toolkits • Example: Enterprise Java Beans from Sun Microsystems • Example: .NET framework from Microsoft

  15. The Internet • The Internet: An internet that spans the world (a worldwide collection of connected networks ) • Original goal was to develop a means of connecting networks that would not be disrupted by local disasters (early 1960s). • Today it has shifted from an academic research project to a commercial undertaking.

  16. Internet Architecture • Internet Service Provider (ISP): Organization which constructs and maintains internet. • Tier-1 : Consist high-speed, high capacity, international WANs (The backbone of Internet) • Tier-2 : More regional ISPs • Access ISP: Provides connectivity to the Internet • Traditional telephone (dial up connection) • Cable connections • DSL • Wireless

  17. Figure 4.7 Internet Composition End systems= hosts

  18. Internet Addressing • IP (Internet Protocol) address: • The unique address of a computer in internet • Pattern of 32 or 128 bits often represented in dotted decimal notation • 17.12.25 = 00010001 00001100 00011001

  19. Internet Addressing • Mnemonic address: • Domain names • Top-Level Domains (edu, com, gov, org etc.) • Country-codeTop-Level Domains (tr, au, ca, etc.) • Domain name system (DNS) • Name server : Translates mnemonic names to IP address • DNS lookup : The process of translation

  20. Internet Corporation for Assigned Names & Numbers (ICANN) • Allocates IP addresses to ISPs who then assign those addresses within their regions. • Oversees the registration of domains and domain names.

  21. Traditional Internet Applications • Electronic Mail (email) • Domain mail server collects incoming mail and transmits outing mail • SMTP: The protocol used to transfer between mail servers as well as to send a new message from it’s author’s local machine to author’s mail server (transfers ASCII text messages MIME: non ASCII) • Mail server delivers collected incoming mail to clients via POP3(Post Office Protocol Version 3) or IMAP(Internet Mail Access Protocol)

  22. Traditional Internet Applications • File Transfer Protocol (FTP) • Telnet : A distant user may contact the telnet server and gain access to the applications and utilities on the computer that a local user has) • SSH : Secured Shell = SecuredTelnet

  23. More Recent Applications • Voice Over IP (VoIP) peer to peerSkype • Internet Radio • Unicast (One sender sending messages to one receiver) • N-unicast (A single sender involved with multiple unicasts) • Multicast (A single sender with multiple clients)

  24. World Wide Web • The World Wide Web, also known as the Web or WWW: • Contains billions of documents • Is a portion of the Internet • Uses the Internet as a means to transport information • Is a separate entity from the Internet

  25. World Wide Web • The Web contains the information. • The Internet transports information to and from users.

  26. World Wide Web • Hypertext : Text file which contains tags to communicate with browser and which contains links to other documents • Hyperlinks or links are words and images that bring other documents into view when clicked • HTTP: Hyper Text Transfer Protocol

  27. World Wide Web • A Web page is a document that may include text, graphics, sound, animation, and video. • A Web site is a collection of Web pages. • A Web browser is a program that displays Web pages and linked items (gets documents from Web server)

  28. Figure 4.8 A typical URL The identification of an Internet resource’s type and location is performed through its Uniform Resource Locator (URL).

  29. Hypertext Document Format • Encoded as text file • Contains tags to communicate with browser • Appearance • <h1> to start a level one heading • <p> to start a new paragraph • Links to other documents and content • <a href = . . . > • Insert images • <img src = . . . >

  30. Figure 4.9 A simple Web page

  31. Figure 4.9 A simple Web page (continued)

  32. Figure 4.10 An enhanced simple Web page

  33. Figure 4.10 An enhanced simple Web page (continued)

  34. Extensible Markup Language (XML) • XML: A language for constructing markup languages similar to HTML • A descendant of SGML • Opens door to a World Wide Semantic Web

  35. Using XML : EXAMPLE <?xml version="1.0"?> <note> <to>Tove</to> <from>Jani</from> <heading>Reminder</heading> <body>Don't forget me this weekend!</body> </note>

  36. Using XML: EXAMPLE <PARTS> <TITLE>ComputerParts</TITLE> <PART> <ITEM>Motherboard</ITEM> <MANUFACTURER>ASUS</MANUFACTURER> <MODEL>P3B-F</MODEL> <COST> 123.00</COST> </PART> <PART> <ITEM>Sound Card</ITEM> <MANUFACTURER>Creative Labs</MANUFACTURER> <MODEL>Sound Blaster Live</MODEL> <COST> 80.00</COST> </PART> </PARTS>

  37. Client Side & Server Side Activities • Client-side activities • Examples: java applets, javascript, Macromedia Flash

  38. Client Side & Server Side Activities • Server-side activities • Common Gateway Interface (CGI): A set of standards by which clients could request execution of programs stored in server • Servlets:Java programs (class) that generate web content dynamically depending on the content of a request from a client • PHP (Hypertext Processor )A widely used, general-purpose scripting language that was originally designed for web development to produce dynamic web pages

More Related