1. McGraw-Hill/Irwin Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved. Extended Learning Module E Network Basics

2. Mod E-2 INTRODUCTION  Computer network – two or more computers connected so that they can communicate with each other and share information, software, peripheral devices, and/or processing power

3. Mod E-3 4 Basic Principles of Networks 1. Each computer must have a network interface 2. The network usually has at least one connecting device 3. The network must have communications media to transport information 4. Each computer must have software to move information on the network

4. Mod E-4 HOME NETWORKS  A typical home network setup has 1. An Ethernet network card in each computer or a wireless card in each laptop 2. Network cables to transmit signals, or radio waves for wireless 3. A DSL or cable modem connection and a broadband/home router

5. Mod E-5 NETWORKS BY DISTANCE  Local Area Network (LAN) – network that serves a building or buildings in a contiguous area  Wide Area Network (WAN) – networks serving areas not immediately contiguous  Metropolitan Area Network (MAN) – networks within the same city or metropolitan area

6. Mod E-6 Broadband Internet Connection  Broadband – high-capacity telecommunications line capable of providing high-speed Internet service  All Internet access methods on the previous slide are broadband except the dialup modem

7. Mod E-7 Digital Subscriber Line (DSL)  Digital Subscriber Line (DSL) – high- speed Internet connection using phone lines, which allows you to use your phone for voice communications at the same time  Runs at a higher frequency than voice conversations, so not supported on some older phone lines

8. Mod E-8 Cable Modem  Cable modem – uses your TV cable to deliver an Internet connection

9. Mod E-9 Satellite Modem  Satellite modem – delivers Internet access by means of a satellite dish  Satellite TV and modem may share same dish or may be separate  Connects to computer or broadband router like cable modem

10. Mod E-10 NETWORK COMMUNICATIONS MEDIA  Communications media – the paths in a network over which information travels  Wired communications media – transmit information over a closed, connected path  Wireless communications media – transmit information through the air

11. Mod E-11 Wireless Communications Media  Infrared – uses red light to send and receive information  Wi-Fi or Wireless Fidelity - a standard for transmitting information in the form of radio waves over distances of about 100 feet  With directional antennas, the distance can be increased to several miles  Wi-Fi hotspots – sites that offer wireless Internet access for your laptop or tablet.

12. Mod E-12 NETWORK SECURITY  The four principles of network security are: 1. Confidentiality 2. Authenticity 3. Integrity 4. Availability

13. Mod E-13 Firewalls & Intrusion Detection Systems  Firewall – protects a computer from intruders  Intrusion detection system (IDS) – watches for and reports intrusion attempts  Intrusion prevention system (IPS) – type of IDS that also takes action against intrusion attempts

14. Mod E-14 Encryption  Encryption – scrambles data so you can't read it without having the decryption key  Virtual Private Network (VPN) – encrypts all network transmissions between two endpoints to protect confidentiality and integrity of data

15. Mod E-15 Malware  Malware – software designed to harm your computer or security 1. Virus – software written with malicious intent to cause annoyance or damage 2. Worm – spreads itself from computer to computer via e-mail and other network traffic 3. Spyware – collects information about you and reports it to someone else without your permission