Unit: The Internet
What is true about computing devices exchanging data over the Internet? A. All the computing devices that are exchanging data over the Internet are following the rules of the Internet Protocol (IP). B. If a computing device attempts to send data to another device and does not follow the Internet protocol (IP) rules, the device will receive a warning from the Internet Protocol Authority (IPA). C. Many computing devices are exchanging data following the rules of the Internet Protocol (IP), but not all devices. The data that isn't sent according to the IP will arrive more slowly. D. As long as a computing device is sending messages over an Ethernet or fiber optic cable, that data will automatically be following the rules of the Internet Protocol (IP).
A. All the computing devices that are exchanging data over the Internet are following the rules of the Internet Protocol (IP). Why? The IP includes rules for message addressing (necessary for routing data from source to destination) and message formatting (necessary for correct interpretation of the data). Two computing devices can only successfully exchange data if they follow the same rules for addressing and formatting.
Which of these is an accurate description of how the TCP/IP protocols send data around the internet? A. Computers split messages into packets and send them through routers to their final destination. The destination computer acknowledges the receipt of each packet so that the sending computer can ensure every packet is delivered. B. Computers split messages into packets. Routers continually send those packets to their final destination. The sending computer does not wait for a response from the receiver to send packets quickly. C. Computers split messages into metadata and data, then send the metadata in a separate packet before sending the data packet. Routers send each packet to the receiving computer. D. Computers split messages into packets, and come up with a routing path for the message. Routers send the message along that path until it reaches its final destination.
A. Computers split messages into packets and send them through routers to their final destination. The destination computer acknowledges the receipt of each packet so that the sending computer can ensure every packet is delivered. Why? When communicating using IP, all messages are split into packets and sent through routers. When using TCP over IP, the recipient sends back an acknowledgment of each received packet, which improves the reliability of transmission.
Which statements are true about computing devices? I. All computing devices are able to run computer programs. II. All computing devices are capable of being interconnected to form computer networks. III. All computing devices have ways to store data for later use. A. I only B. II only C. III only D. I and II only E. I, II, and III
A. I only Why? A computing device is a physical device that can run a program. It does not necessarily have networking hardware or long-term storage.
A new Internet provider ZoomyZoomy is creating advertising that focuses on the bandwidth of their connections. Which of these slogans has the correct unit? A. Sign up now for a bandwidth of 50 megabits/second! B. Sign up now for a bandwidth of 50 seconds/megabit! C. Sign up now for a bandwidth of 50 milliseconds! D. Sign up now for a bandwidth of 50 megabits!
A. Sign up now for a bandwidth of 50 megabits/second! Why? Bandwidth is a measurement of how much data can be transferred in a fixed period of time. It's typically measured in multiples of bits per second, such as Kbps (kilobits/second), Mbps (megabits/second), and Gbps (gigabits/second).
One problem with packet-based messaging systems like the Internet Protocol is that packets might arrive out of order. TCP is a protocol that can deal with out-of-order packets. When used over IP, each packet contains a TCP segment with metadata and data. Which of the following best describes how TCP can reassemble out-of-order packets? A. The TCP metadata includes fields that describe where the packet belongs in the sequence. B. The TCP metadata and data can be combined to figure out where that packet belongs in the sequence. C. A separate packet (received after all the packets with data have arrived) contains information on the sequence of the data packets. D. The TCP data includes information at the beginning that describes where the packet belongs in the sequence.
A. The TCP metadata includes fields that describe where the packet belongs in the sequence. Why? The TCP metadata helps with the reliability aspects of TCP, such as packet reassembly and packet retransmission. Specifically, TCP uses the sequence number in the metadata to reassemble packets in the correct order.
Which of these best describes the fault tolerance of routing on the Internet? A. There are multiple routes for each IP packet to follow. A packet can be re-routed if a path becomes unavailable. B. IP addresses are hierarchical, so routing tables can store routes by prefix, and thus not have to store as large of a table. C. IP v6 addresses are much larger than IP v4 addresses, so packets can be sent to a larger number of computers. D. An IP packet contains the Source/Destination address, so the router can pick the next path to send it down.
A. There are multiple routes for each IP packet to follow. A packet can be re-routed if a path becomes unavailable.
Which of these situations describes a computer network? A. A programmer runs a program using parallel computing on their multi-CPU computer. Each CPU processes a different part of the program and stores the final results in shared memory. B. A company gives every employee a desktop computer and connects each of the computers using wires so that they can quickly transfer files and messages. C. A plant biologist inserts a moisture sensor into the soil of a potted plant. The moisture sensor records the moisture every minute and saves it onto an SD card for storage. D. A smartphone store displays 20 different smartphones for shoppers to try out. All the smartphones are on a long table and plugged into a single power strip.
B. A company gives every employee a desktop computer and connects each of the computers using wires so that they can quickly transfer files and messages. Why? A computer network is a group of interconnected computing devices capable of sending or receiving data. This situation describes a company's internal computer network (often called an intranet), which is common at companies that want to connect their own computers together without exposing them to the dangers of the global Internet.
IPv4 is the first standardized version of the Internet Protocol. IPv4 is gradually being replaced by IPv6, a more scalable version of the protocol. Which feature of IPv4 makes it a less scalable system? A.IPv4 systems can use Network Address Translation (NAT) to allow a single IP address to represent multiple devices. Typically a router's IP address is used for transfer over the Internet, and then the router can send the data to one of the devices connected to it with the use of internal IP addresses. B.Each IPv4 address is a 32-bit number. That's enough space for 2^{32}2322, start superscript, 32, end superscript (4.3 \times 10^{9}4.3×1094, point, 3, times, 10, start superscript, 9, end superscript) possible addresses for Internet-connected computing devices (less than the current number of Internet-connected devices). C.IPv4 includes a checksum field in the header to enable routers to make sure the header was not corrupted (maliciously or accidentally) in transport. D.Each IP packet header includes (optional) options fields that can be used by different Internet applications to change the way packets are routed or handled at the destination.
B. Each IPv4 address is a 32-bit number. That's enough space for 2^{32}2322, start superscript, 32, end superscript (4.3 \times 10^{9}4.3×1094, point, 3, times, 10, start superscript, 9, end superscript) possible addresses for Internet-connected computing devices (less than the current number of Internet-connected devices). Why? A scalable system is one that can remain effective even when there is a significant increase in the number of users of the system. The IPv4 address space was not large enough to uniquely identify all the devices that want to use the system. IPv4 did not scale to meet the demand.
When packets are routed on the Internet, the route for a particular packet is not pre-determined. Instead, the next hop is decided by each router along the way. How does that increase the fault tolerance of routing on the Internet? A. Each router can pick a connection that's closest to the destination. B. Each router can pick a connection that's currently working and available. C. Each router can decide to pick a connection that has higher bandwidth. D. Each router can decide whether to discard the packet.
B. Each router can pick a connection that's currently working and available. Why? This improves the fault tolerance since a router can see when a connection is suddenly unavailable and send a packet down a different connection instead.
In the Internet Protocol (IP), computers send messages to each other through a network of routers, with each message split up into packets. How do routers determine where a packet needs to go? A. Routers look up the packet ID in a database, and find the destination address in the database. B. Routers look at the IP packet header and use the destination address field. C. Routers ask DNS servers for the final destination of each packet. D. Routers make best guesses based on the content of the packet data. E. Routers wait for subsequent packets that contain the destination address.
B. Routers look at the IP packet header and use the destination address field.
Every year during the Christmas holiday, Google hosts a website to help track the path of Santa around the globe. The website goes from zero traffic to millions of visitors in a small period of time. Before the website goes live, site reliability engineers (SREs) are in charge of making sure that the Santa tracking website will be able to withstand the spike in traffic. Which of these strategies is the best way to verify that the Santa tracking website is scalable? A. The SREs can use common hacking techniques to try to breach the web site's database and uncover security holes. B. The SREs can use Google-owned machines to simulate large amounts of visitors on the website and monitor the website to see how it reacts. C. The SREs can preview the website at multiple screen sizes and on multiple types of devices to ensure it looks correct in all shapes and sizes. D. The SREs can write tests to make sure that the site correctly reports the current location of Santa at all times.
B. The SREs can use Google-owned machines to simulate large amounts of visitors on the website and monitor the website to see how it reacts. Why? A scalable system is one that remains effective even with high numbers of users. Simulating large amount of users is a good way to assess the scalability of a system.
The following passage describes the Internet but contains a missing adjective: The Internet is a loosely organized international collaboration of interconnected networks. Even though the computing devices belong to a wide range of companies, individuals, and governments, all the devices on the Internet can successfully communicate with each other thanks to the <???> nature of Internet protocols. What is the most appropriate adjective to replace <???>? A. efficient B. open C. authenticated D. proprietary
B. open Why? An "open" protocol is nonproprietary and described in publicly available documents. Since there is no company that owns the protocol, a computer network administrator does not need to pay a fee to read or implement the protocol. That enables computing devices around the world to connect to other computing devices over the Internet.
Which of the following least illustrates inequity caused by the digital divide? A. A citizen of a country with limited freedoms is unable to share their story of living in that country, as their country has no publicly available connections to the Internet. B. A senior citizen becomes lonely and depressed because their family members use digital technology to communicate and they're not sure how to use it correctly. C. A new company enters a competition to win funding but they do not win and have to shut down due to lack of funds. D. A citizen of a bilingual country is unable to use a government website because the user interface is not translated into the language that they speak.
C. A new company enters a competition to win funding but they do not win and have to shut down due to lack of funds. Why? A digital divide describes the difference in access to computers and the Internet, but this situation describes solely a difference in access to money.
When a computer loads a webpage, it sends a message to a web server over the Internet. How many Internet protocols are used to send and receive the message? A. It uses only one protocol B. It only uses a protocol if the message must be encrypted C. It always uses multiple protocols D. It uses one protocol to load an unsecured webpage but two protocols to load a secure webpage
C. It always uses multiple protocols
A copywriter is writing a help center article for a video conferencing service. This is their draft so far: Bandwidth requirements Recommended bandwidth for meetings: For high-quality video: 600 <UNIT> For screen sharing only: 75 <UNIT> For audio call only: 80 <UNIT> What would be the most appropriate unit to replace <UNIT>? A. Seconds per kilobit B. Seconds C. Kilobits per second D. Kilobits
C. Kilobits per second Why? Bandwidth is a measurement of how much data can be transferred in a fixed period of time. "Kilobits per second" conveys how many kilobits are transferred in one second, so it is an appropriate unit for the article.
Why does each IP packet contain a destination address? A. Routers can see where a packet came from by examining the destination address and make sure not to send it back. B. Computers can look at the destination address to see if the packet has been hijacked along the way. C. Routers use the destination address to decide where to send a packet next. D. The web browser uses the destination address to decide what URL to show in the browser address bar. E. Computers use the destination address to figure out how to reassemble IP packets in the correct order.
C. Routers use the destination address to decide where to send a packet next.
Which of the following statements about IP addresses is true? A. If an Internet User wishes to receive an email, they must sign up for an IP address. B. In modern times, every computing device that is manufactured is assigned an IP address before it is sold. C. When data is sent between devices on the Internet, they identify each other with an IP address. D. Any computing device that is part of a computer network has an IP address.
C. When data is sent between devices on the Internet, they identify each other with an IP address. Why? According to the Internet Protocol (IP), a device that wants to send information over the Internet must identify the destination with an IP address.
Which of these statements about the digital divide is true? A. As long as someone owns a smartphone with Internet access, they're not affected by the digital divide. B. The digital divide only happens in developing nations, not in countries like America or the UK. C. There's no digital divide among young people, only between young and old people. D. Even for-profit companies can take actions to help bridge the digital divide.
D. Even for-profit companies can take actions to help bridge the digital divide.
Which of the following kinds of computing devices use the Internet Protocol (IP) when sending data over the Internet? I. A tablet computer II. A desktop computer III. end text. A smartphone A. II only B. III only C. I and II only D. I, II, and III
D. I, II, and III Why? Many types of computing devices can be connected to the Internet. Any device that sends data over the Internet must use the Internet Protocol to do so.
Many people worry about what would happen if either the Internet or the World Wide Web went down (if they suffered a complete outage and were unreachable). Which of these predictions is correct? A. If the World Wide Web went down, the Internet would also go down, since the Internet relies on the WWW protocols. B. If either the Internet or the World Wide Web goes down, the other system will not necessarily go down as well, as they are fully independent of each other. C. If either the Internet or the World Wide Web goes down, both systems would have to go down together since they are interdependent. D. If the Internet went down, the World Wide Web would also go down, since the WWW relies on Internet protocols.
D. If the Internet went down, the World Wide Web would also go down, since the WWW relies on the Internet protocols. Why? The WWW runs on top of the Internet. It was invented after the Internet had already been around for a few decades, so it could take advantage of the existing Internet protocols and infrastructure.
How does the Internet Protocol (IP) fit into the Internet technology suite? A. The Internet Protocol is the only protocol that powers communication on the Internet. B. The Internet Protocol is one of many protocols in the Internet technology stack but isn't used as frequently as other protocols. C. The Internet Protocol was recently proposed and is slowly replacing the old protocols that powered the original Internet. D. The Internet Protocol is a protocol used in all Internet communication, but other protocols are also used.
D. The Internet Protocol is a protocol used in all Internet communication, but other protocols are also used. Why? The Internet Protocol describes both addressing and routing, so every message sent over the Internet must follow the rules described in the protocol.
Which statement is true about packet loss on the Internet? A.As long as two computers are using the Internet Protocol (IP), the packets that they send to each other can never be lost. B. When two computers are using the Internet Protocol (IP), the packets that they send to each other can be lost along the way, but they can be recovered via retransmission. C. As long as two computers are using the Transmission Control Protocol (TCP), the packets that they send to each other can never be lost. D. When two computers are using the Transmission Control Protocol (TCP), the packets that they send to each other can be lost along the way, but they can be recovered via retransmission.
D. When two computers are using the Transmission Control Protocol (TCP), the packets that they send to each other can be lost along the way, but they can be recovered via retransmission. Why? TCP is a data transport protocol that works on top of IP and includes mechanisms to improve the reliability, such as retransmission of lost packets.