APCPSP semester exam MC

Which of the following statements are true about routers and routing on the Internet.

-A packet traveling between two computers on the Internet may be rerouted many times along the way or even lost or "dropped". -Routers act independently and route packets as they see fit.

The various protocols in use on the internet are said to operate in layers in which the protocol(s) at each layer solve one problem related to networked communication, and higher layers are built on top of, and rely on, the lower layers to do their jobs. From the list provided choose the two (2) answers that correctly describe which internet protocol relies on the other. For example: if protocol A relies on protocol B, it means that A is a higher level protocol than B, and thus protocol B must exist and work properly in order for protocol A to do its job.

-HTTP relies on TCP/IP -DNS relies on TCP/IP

What is the 4-bit binary number for the decimal number Ten (10)

1010.

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 integers instead of 32-bit integers? A. 2 times as many values can be represented. B. 32 times as many values can be represented. C. 2^32 times as many values can be represented. D. 32^2 times as many values can be represented. Answer

2^32 times as many values can be represented.

The world is currently in a transition to using IPv6, a newer version of the IP protocol that uses 128-bit addresses instead of 32-bit addresses used by IPv4. What is the main problem that IPv6 was created to solve?

32-bit addresses could not ensure that every internet connected device can receive a unique IP address

What is the minimum number of bits you would need to encode the 26 letters of the alphabet plus a space- a total of 27 characters?

5 bits.

8 bits is enough to represent 256 different numbers. How many total bits do you need to represent 512 (twice as many) numbers?

9 bits.

The Internet Engineering Task Force defines the protocols and standards for how the Internet works. The members of the IEFT are:

A loosely organized collection of citizens and engineers.

A middle school is expanding to open a high school next year, doubling the total number of students. The school keeps a database in which each student's unique ID number is stored as an 8 bit number called studentID. Before the arrival of the new students almost every 8 bit number has already been assigned to a student. Which is the most accurate description of how the school could modify the way studentID is represented in the database to ensure each incoming student receives a unique ID?

Add a bit to studentID to double the number of IDs that the database can represent.

The figure represents a network of physically linked computers labeled A through F. A line between two computers indicates that the computers can communicate directly with each other. Any information sent between two computers that are not directly connected must go through at least one other computer. The weight or cost of sending information from one computer to another is indicated by the number above the line. For example, information can be sent directly between computers A, and B and will cost 5. Information sent between computers A and D must go through either computer C (with total cost 5), or through computer B (with total cost 8) (Image Not Available) Question: Computer A sends a packet intended to reach computer F. Along its path it arrives at Computer C. Which computer should Computer C forward the packet to in order to use the most cost effective path?

Computer D

Consider the following numbers given in Binary (BIN), Decimal (DEC), and Hexadecimal (HEX) representations: BIN: 1110 DEC: 13 HEX F Which of the following lists the numbers in order from least to greatest?

DEC: 13, BIN: 1110, HEX: F

How does a computer resolve a domain name into an IP address?

It asks a DNS server for the corresponding IP address

What is the best explanation for why digital data is represented in computers in binary?

It's easier, cheaper, and more reliable to build machines and devices that only have to distinguish between binary states.

A user clicks on a website, and it begins to load immediately, but it takes a long time to load completely and pictures appear slowly, one by one. Which of the following is demonstrated through this situation?

Low bandwidth, low latency.

Which of the following BEST describes how protocols on the Internet (e.g. IP, TCP, HTTP) make use of abstraction to accomplish their respective purposes?

Low level protocols can provide functionally to high level protocols without revealing the details of how this is accomplished

Which of the following is NOT true about TCP/IP packets?

TCP guarantees that no packets are ever dropped

Number bases, including binary, decimal, and hexadecimal, are used to view and represent digital data. Which of the following is NOT true about representing digital data?

There is a limit to the number of things that can be represented in binary data at which point switching to hexadecimal representation is necessary.

The next question refers to hexadecimal which is a base-16 number system - a number system that uses one of 16 possible digits for each place value. You may not have explicitly covered hexadecimal in your class yet, that's okay. Consider this a challenge question and try your best using your intuition about what you already know. The 16 digits used in hexadecimal are: 0 1 2 3 4 5 6 7 8 9 A B C D E F. These represent the decimal values 0-15, respectively. Hex is just another number system so, for example the value "fourteen" can be represented in Decimal, Binary and Hexadecimal like so: Decimal: 14 Binary: 1110 Hexadecimal: E ASCII is a character-encoding scheme that uses a numeric value to represent each character. For example, the uppercase letter "G" is represented by the decimal (base 10) value 71. A partial list of characters and their corresponding ASCII values are shown in the table below. (Image not available) ASCII characters can also be represented by hexadecimal numbers. According to ASCII character encoding, which of the following letters is represented by the hexadecimal (base 16) number 56?

V.

A school starts tracking which websites each computer in the school is visiting by monitoring the packets leaving the school. A sample of the information they have collected appears below: (Image Not Available) Which of the following is MOST likely to be answerable using all the data collected by this monitoring?

Which websites are most frequently visited before and after school hours from a school computer

According to the domain name system (DNS), which of the following is a sub domain of the domain example.com?

about.example.com