1 / 24

Introduction to Networks: Types, Applications, and Security

Learn about different types of networks, network applications, physical networking, information storage, exchange, network security, and internet fundamentals in this lecture.

lauriee
Download Presentation

Introduction to Networks: Types, Applications, and Security

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. Networks CPS120 Introduction to Computer Programming Lecture 4

  2. What Is a Network • A network is a group of connected computers that allow people to share information and equipment

  3. Types of Networks • LAN (Local Area Network) connects computers within a small geographic area like a building • WAN (Wide Area Network) connects computers across a large geographic area like a city or country (often via satellite) • Internet: World-wide network of networks

  4. Advantages • Road warriors • Eliminate “sneakernet” • Share information • Share equipment

  5. Who Runs It? • A network administrator manages the network and makes sure it runs smoothly • Often called a systems administrator or an IS manager

  6. Network Applications • Electronic mail • Groupware • Calendaring • Scheduling • Video-conferencing • Requires sound card, speakers, mike & camera

  7. Physical Networking • Hubs • A hub is a device that provides a central location where all the cables on a network come together • NICs (Network Interface Card) • An expansion card that physically connects each computer to the network • Cables • Coaxial, Unshielded Twisted Pair (UTP), Shielded Twisted Pair, Fiber-optic • Wireless

  8. How Information Is Stored • Client-Server: • Used for large networks • Files are stored on a central computer and everyone who can access the network can be given access them • Easy to create scheme to backup and protect files • Client: a computer that can access information stored on the server • Server: Central computer that stores files • NetWare, UNIX, Windows NT/2000

  9. How Information Is Stored • Peer-to-Peer: • Used for a small number of computes (e.g. 10) • Files stored on own computers; access given to them to others on the network • LANtastic, Windows-98, Windows-ME

  10. How Information Is Exchanged • Ethernet: • Most popular and least expensive solution • Each computer waits for a pause before sending information • Like polite conversation • Collisions between information often occur • Computers wait a moment, then resend • Ethernet – 10 Mbps, Fast Ethernet – 100 Mbps, Gigabit Ethernet 1000 Mbps

  11. How Information Is Exchanged • Token-ring is a type of network where a token that collects and delivers information is passed from compute to computer • Speeds of 4 or 16 Mbps • Asynchronous Transfer Mode (ATM) is a type of network that works by sending information in equal-sized pieces called cells • 25, 155, 622 or 2488 Mbps • Often networks networks

  12. Network Security • Firewall – specialized hardware or software package designed to protect a private computer network from unauthorized access • Think “Moat” • User name and password • Used for authentication • Good passwords

  13. Intranet • Small version of the Internet in a company • Uses familiar web-browsers and email packages • Allows hyper-linking • VPNs (Virtual Private Network) • End-to-end encryption • More cost efficient than private lines

  14. Internet and WWW Chapter 10

  15. Internet Fundamentals • Dates from DARPA in the 1960s • Consists of thousands of connected networks around the world • Each organization on the Internet is responsible for maintaining its own equipment • These organizations allow you to pass-through their nets • Designed to provide multiple routing to bypass disabled computers • Called cyber-space or the information superhighway

  16. Internet Offerings • Electronic mail (Most popular application) • Information • Entertainment • Discussion Groups • Chat • Programs (Shareware) • Online shopping

  17. Connecting • Computer • Software • Modem or high-speed connection • ISP (Internet Service Provider) • Access for a fee

  18. World Wide Web • Part of the Internet consisting of a huge collection of documents stored on computers around the world • Web server: computer that stores and delivers web pages • Web site: collection of web pages • URL (Uniform Resource Locator) – unique address • HTTP, Computer, Directory, Name of Page • Hyperlinks jump to different web pages

  19. Browsers • A program that lets you view and navigate information on the World Wide Web • Home Page: Web page that appears each time you start your web browser • Browser: • Internet Explorer • Netscape Navigator • Features • Bookmark • History lists

  20. Multimedia • MP3 – compressed files containing music or video • WinAmp • Streaming video – requires player • RealPlayer, QuickTime • Enhancements • Java • JavaScript • ActiveX

  21. Web Portal • Central starting point for browsing personalized by the individual • Yahoo, Excite, Go, Lycos • Info • Free services like email, shopping, chat, games, stock quotes and sports scores

  22. Shopping • Auctions • Secure web sites – i.e. HTTPS

  23. Children on the Web • Inappropriate information • Pictures • Documents • Protection • Adult supervision • Browser restrictions • Restriction programs • CyberPatrol • NetNanny

  24. Create & Publish Web Pages • HyperText Mark-up Language is a computer code used to create Web pages • There are many programs available, called visual editors which can help you create Web pages without having to learn HTML • Publishing your pages – loaded to an addressable server

More Related