1. N ETWORK S YSTEMS 3.02 U NDERSTAND C ONNECTIVITY THROUGH NETWORKS AND THE I NTERNET

2. Networks and the Internet Transmission Media Network Types Data Flow Internet Speed Security Risks COURSE CONTENT

3. Protect The Data Learn How Data Flows Understand Media GOALS

4. Definition Provides a path for information to be sent from one computer to another through a network Types of Transmission Media: Coaxial cable Ethernet cable Fiber optic cable Wireless transmission TRANSMISSION MEDIA

5. Definition Cable specifically designed for carrying an electronic signal Features: Cable Length (200 – 500 meters) Cost (Ethernet < Coaxial < Fiber Optic) Ease of Installation (Moderately difficult to install) Susceptible to EMI and RFI interference Consists of four layers of material to reduce interference COAXIAL CABLE

6. Definition Cable commonly used in high-speed wired computer networks Features: Cable Length (Up to 100 meters) Cost (Ethernet is the cheapest) Ease of Installation (Easy to install) Susceptible to EMI and RFI interference Twisted pair wiring reduces interference Types Straight-through Crossover Rollover ETHERNET CABLE

7. Definition Cable made of super-thin filaments of glass or other transparent materials that can carry beams of light Features: Cable Length (Longest transmission, use of light) Cost (Fiber Optic is most expensive) Ease of Installation (Difficult to install) FIBER OPTIC CABLE

8. More Features: Less susceptible to interference Data can be sent at the speed of light. A LASER transmitter encodes frequency signals into pulses of light: ones and zeros are sent through the cable. The receiving end of the transmission translates the light signals back into data which can be read by a computer. FIBER OPTIC CABLE

9. Definition Able to connect computers to other computers and printers the same way a wired network is, but without wires and a slower connectivity Features: Range (Depends on factors such as wireless card, access point, and obstacles in between) Cost (Wireless price is dependent upon the complexity of the setup.) Ease of Installation (Easy) 802.11 (a,b,g,n) Interference caused by cordless telephones and microwaves WIRELESS TRANSMISSION

10. Intranet A private network that facilitates communication between departments of an organization or business Intranets are accessible by employees inside the organization. Cannot be accessed from the outside without the use of an extranet LIMITED NETWORK CONNECTIVITY Admin Shipping Personnel

11. Extranet A network that allows limited access from outside a private network associated with a company Used for business partners and employees to conduct business from remote locations Allows business partners to access data to speed up shipping or manage services. LIMITED NETWORK CONNECTIVITY Admin Shippin g Personnel Home Extranet

12. Based on data flow Data flow is the flow of bits of data from one device on the network to another. Encapsulation – The creating and formatting of the data to be sent. De-encapsulation – The removal of the control information of the message once it reaches the destination. INTERNET CONNECTIVITY

13. Bandwidth – Theoretical amount of data that can be transmitted across a given medium Throughput – The actual amount of data that can be transmitted across a given medium Units of Measurement: Bits per second (bps) = a small text message Kilobits per second (Kbps) = a text document Megabits per second (Mbps) = one or two photos Gigabits per second (Gbps) = a movie MEASURING INTERNET DATA FLOW

14. Bandwidth refers to ideal conditions for network speed. How fast could you go if you were the only car on the highway? BANDWIDTH

15. Throughput accounts for the resistance of the medium (the road in this case). What if the road wasnt straight, or there was road construction? THROUGHPUT Network Limitations: Data type Topology Congestion Computer processing Network Limitations: Data type Topology Congestion Computer processing

16. CATEGORIES OF INTERNET SPEED

17. The speed at which a user can retrieve data from the Internet DOWNLOAD SPEED

18. The speed at which a user can send data to a remote location on the Internet UPLOAD SPEED

19. The lag, or length of time, that occurs between each point during information transfer LATENCY

20. LINKING TO THE INTERNET

21. To link to the Internet, the user needs to set up service with a company that has a permanent connection and that can provide temporary access to users INTERNET SERVICE PROVIDER

22. To connect to the Internet, a computer must have a unique identifier INTERNET PROTOCOL ADDRESS

23. SECURITY RISKS

24. An intrusion to the network Types: Hacker Phishing Spyware Adware Malware UNAUTHORIZED ACCESS

25. A person who finds and exploits weaknesses of a computer HACKER

26. The act of masquerading as a trustworthy website or other entity to acquire user information PHISHING

27. Malicious software meant to gain access, disrupt computer operation, or gather sensitive information MALWARE

28. A type of malware that collects user information by tracking the habits of users SPYWARE

29. Advertising software that automatically generates advertisements ADWARE

30. A computer program that replicates itself VIRUS

31. A form of malware that uses the network to spread from host to host WORM

32. A standalone, malicious program that gives access from the infected computer to another computer TROJAN HORSE

33. An attempt to use anothers identity to commit a crime IDENTITY FRAUD

34. User awareness and education Anti-virus software Firewalls Passwords Complex Confidential Varied and changed regularly PREVENTION METHODS