Vocabulary DNS DDoS HTTP HTML IP Address TCP URL a. The song was saved using fewer bits per second than the original song.

Transcription

1 Vocabulary DNS - The Domain Name System (DNS) is the service that translates URLs to IP addresses. DDoS - A Distributed Denial of Service (DDoS) attack is an attempt to make an online service unavailable by overwhelming it with traffic from multiple sources. HTTP - HyperText Transfer Protocol - the protocol used for transmitting web pages over the Internet HTML - is a markup language for describing web documents (web pages). HTML stands for Hyper Text Markup Language. IP Address An Internet Protocol (IP) Address is a number assigned to any item that is connected to the Internet. TCP - Transmission Control Protocol - provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. TCP is tightly linked with IP and usually seen as TCP/IP in writing. URL - A Uniform Resource Locator (URL), is an easy-to-remember address for calling a web page (like 1. A student is recording a song on her computer. When the recording is finished, she saves a copy on her computer. The student notices that the saved copy is of lower sound quality than the original recording. Which of the following could be a possible explanation for the difference in sound quality? a. The song was saved using fewer bits per second than the original song. b. The song was saved using more bits per second than the original song. c. The song was saved using a lossless compression technique d. Some information is lost every time a file is saved from one location on a computer to another location

2 2. A user enters a Web address in a browser, and a request for a file is sent to a Web server. Which of the following best describes how the file is sent to the user? a. The file is broken into packets for transmission. The packets must be reassembled upon receipt. b. The file is broken into packets for transmission. The user s browser must request each packet in order until all packets are received. c. The server attempts to connect directly to the user s computer. If the connects is successful, the entire file is sent. If the connection is unsuccessful, an error message is sent to the user. d. The server repeatedly attempts to connect directly to the user s computer until a connection is made. Once the connection is made, the entire file is sent. 3. An online store uses 6-bit binary sequences to identify each unique item for sale. The store plans to increase the number of items it sell and is considering using 7-bit binary sequences. Which of the follow best describes the result of using 7-bit sequences instead of 6-bit sequences? a. 2 more items can be uniquely identified b. 10 more items can be uniquely identified c. 2 times as many items can be uniquely identified. d. 10 times as many items can be uniquely identified.

3 4. ASCII is a character-encoding scheme that uses 7 bits to represent each character. The decimal (base 10) values 65 through 90 represent the capital letters A through Z, as shown in the table below. Decimal ASCII Character Decimal ASCII Character 65 A 78 N 66 B 79 O 67 C 80 P 68 D 81 Q 69 E 82 R 70 F 83 S 71 G 84 T 72 H 85 U 73 I 86 V 74 J 87 W 75 K 88 X 76 L 89 Y 77 M 90 Z What ASCII character is represented by the binary (base 2) number ? a. H b. I c. J d. K 5. ASCII characters can also be represented by hexadecimal numbers. According to ASCII character encoding, which of the follow letters is represented by the hexadecimal (base 16) number 56? a) A b) L c) V d) Y

4 6. Which of the following best explains what happens when a new device is connected to the Internet? a. A device drives is assigned to the device b. An Internet Protocol (IP) address is assigned to the device c. A packet number is assigned to the device d. A Web is assigned to the device. 6. Consider the following numbers. Binary 1100 Decimal 11 Hexadecimal D Which of the following lists the numbers in order from least to greatest? a. Binary 1100, Decimal 11, Hexadecimal D b. Decimal 11, Hexadecimal D, Binary 1100 c. Hexadecimal D, Binary 1100, Decimal 11 d. Decimal 11, Binary 1100, Hexadecimal D 7. A computer program uses 3 bits to represent integers. When the program add the decimal (base 10) numbers 5 and 3, the result is 0. Which of the following is the best explanation for the result? a) An overflow error occurred. b) A round-off error occurred. c) The result was affected by lossy data compression. d) The result was approximated by a floating-point representation.

5 8. Which of the following can be represented by a single binary digit? Select TWO answers. a) The position of the minute hand of a clock b) The remainder when dividing a whole number by 2 c) The value of a Boolean variable d) The volume of a car radio 9. A video-streaming Web site uses 32-bit integers to count the number of times each video has been played. In anticipation of some videos being played more times than can be represented with 32 bits, the Web site is planning to change to 64-bit integers for the counter. Which of the following best describes the result of using 64-bit inters instead of 32-bit integers? a) 2 times as many values can be represented b) 32 times as many values can be represent c) 2 32 times as many values can be represented d) 3 22 times as many values can be represented. 10. The Internet Engineering Task Force (IETF) defines the protocols and standards for how the Internet works. The members of the IETF are: a) An International coalition of government agencies who oversee the Internet in their countries. b) The worldwide leaders of the Tier 1 internet service providers. c) A loosely organized collection of citizens and engineers who communicate mostly by . d) Political leaders and heads of state 11. What is an RFC? a) Restricted Fiduciary Contract b) Request For Comments c) Radio Frequency Controller d) Related Fundamental Content

6 12. Choose the two best answers to complete the sentence: If I understand how the internet works then I will be able to: a) Make informed choices to support or oppose decisions my government makes about access to the internet. b) Connect the latest devices to the internet. c) Make informed choices about my privacy on the internet d) Get the best price for my cell phone plan 14. What is an IP Address? a) A number assigned to an item or device that is connected to the internet b) The address of the DNS c) Small chunks of information that have been formed from larger chunks of information. d) A set of rules governing the exchange or transmission of data between devices. 15. What is an IP Packet? a) A number assigned to an item or device that is connected to the internet b) The address of the DNS c) Small chunks of information that have been formed from larger chunks of information. d) A set of rules governing the exchange or transmission of data between devices. 16. How many users would a fixed-length IP address system using 6 bits support? a) 6 users b) 12 users c) 32 users d) 64 users

7 17. What is a router? a) Used to translate computer hostnames into IP addresses. b) A computer which receives messages traveling across a network and redirects them towards their intended destinations based on the addressing information included with the message c) A number assigned to an item or device that is connected to the internet d) Small chunks of information that have been formed from larger chunks of information. 18. What is the purpose of the Domain Name System (DNS)? a) Used to translate computer hostnames into IP addresses. b) A computer which receives messages traveling across a network and redirects them towards their intended destinations based on the addressing information included with the message c) A number assigned to an item or device that is connected to the internet d) Small chunks of information that have been formed from larger chunks of information. 19. According to the domain name system (DNS) which of the following is a subdomain of the domain example.com? a) about.example.com b) example.co.uk c) example.com.org d) example.org 19. Choose two: Pick the two statements about packets and routing on the Internet which are true. a) Packets travelling across the Internet take a standardized amount of time and so can be counted on to arrive in the order they were sent. b) TCP ensures messages can be reliably transmitted across the Internet. c) TCP depends on the infrastructure of the Internet to be reliable enough to ensure no packets are lost in transmission. d) TCP must account for the fact that packets may not arrive at a destination computer in the intended order.

8 20. Which of the following is NOT true about packets? a) Packets are numbered, so if they arrive out of order, the message can be reassembled. b) A message sent across the Internet can always be contained in a single packet. c) Packets are routed on different paths from sender to receiver. d) The receiver computer must confirm to the sending computer that each packet was received. 21. A single central register of IP addresses and names (i.e. a DNS-style system) is an efficient means of translating human-readable names to IP addresses. Which of the following is NOT solved by DNS? a) It s inefficient to have everyone on the Internet maintain their own list of IP addresses. b) There are too few IP addresses to meet the current demand. c) When someone new joins the Internet, they need to inform everyone of their IP address. d) When an IP address changes, it is impossible to locate a computer until the owner announces the change. 22. Which of the following best describes a Distributed Denial of Service (DDoS) attack? a) An attempt by a country to deny its citizens access to the Internet b) An attempt to deny users access to a Web site s resources by flooding the Web site with requests from multiple systems c) An attempt by one user to deny service to another user by posting material on a social network d) An attempt by a user of the Internet to get private information from a secure database. 23. What is a Protocol? a) A number assigned to an item or device that is connected to the internet

9 b) The address of the DNS c) Small chunks of information that have been formed from larger chunks of information. d) A set of rules governing the exchange or transmission of data between devices. 24. Two computers are built by different manufacturers. One is running a Web server and the other is running a Web browser. Which of the following best describes the ability of the two computers to communicate with each other across the Internet? a) The computers cannot communicate because different manufacturers use different communication protocols. b) The computers can communicate, but additional hardware is needed to convert date packets from one computer s protocol to the other computer s protocol. c) The computers can communicate directly only if the messages consist of text; other formats cannot be interpreted across computers. d) The computers can communicate directly because Internet communication uses standard protocols. 25. Researchers have developed a simulation of packets traveling between server computers and client computers in a network. Of the following, which two outcomes are most likely to be results of the simulation? 26. Select two answers. a) Better understanding of the effect of temporarily unavailable network connections. b) Better understanding of the effect of using hexadecimal representations for binary data c) Better understanding of the impact of access to public data in identifying solutions to problems d) Better understanding of the impact of increased connection speeds for frequently visited servers

10 27. Multiple Choice: HTTP is considered to be a high-level protocol because: a) HTTP requests are given higher priority for fast delivery when being routed on the Internet. b) HTTP requests are encoded using higher-frequency radio waves. c) HTTP messages can be either requests or responses. d) HTTP requests make use of abstractions provided by lower-level protocols. 28. Choose Two: Choose the two true statements about HTTP: a) An HTTP request is sent from a client to request access to data stored on a server. b) HTTP requests and responses have identical formats. c) Displaying a web page will often require multiple HTTP requests in order to acquire all the necessary data. d) An HTTP response code is only used when a server could not fulfill a request.