khan academy unit: computing innovations

Which of these statements about the digital divide is true? pt2

A country which has the majority of its population online could suddenly shut down their citizen's access to the Internet for political reasons.

In the field of computer networks, what is a protocol?

A documented set of rules that describe the behavior of devices in the computer network

Feiya has several computing devices around the home that are connected to the Internet: A smart home assistant (connected via wireless) A laptop computer (connected via wireless) A desktop computer (connected via Ethernet) Which of her devices use the Internet Protocol (IP) when sending data through the Internet?

All of the devices

Benjamin is writing code for a medical software company. He would like feedback on his code and is considering either asking a colleague for an in-person code review or uploading the code to a collaborative code review program. What would be the most likely advantage of using collaborative code review software?

Multiple colleagues could see his code and give feedback on ways to improve it.

How many protocols are used when a message is sent over the Internet?

Multiple protocols are used when a message is sent over the Internet. The computer uses the stack of protocols that are most fitting for the type of message.

Which of these is not a protocol that powers the Internet?

PII/ API

Internet routing is designed to be fault tolerant. What implications does that have for the Internet's performance during a natural disaster? Choose 1 answer:

The Internet can keep routing messages as long as enough routes stay available, but it could be brought down entirely.

When a website is endorsed by celebrity on social media, the website often experiences a surge in users. Which of these charts represents a website scaling well to handle a surge in users? The purple line shows all the requests sent to the website servers, while the red dashed line shows which of the requests resulted in a server error.

purple line going up red line on the bottom basically straight

What is true about the computing devices exchanging data over the Internet?

All the computing devices that are exchanging data over the Internet are following the rules of the Internet Protocol (IP).

Loke used a tool to track the route taken by an IP packet from their school computer to the IP address of the KhanAcademy.org server. Here are the results: If Loke runs the tool again, what output would he expect to see?

He might see the same stops or might see a different sequence of stops.

Which of these are a requirement for a computer to access the Internet? \text{I}Istart text, I, end text. A web browser that can load websites and associated multimedia files \text{II}IIstart text, I, I, end text. The ability to connect that computer to another Internet-connected device \text{III}IIIstart text, I, I, I, end text. An encryption key used to secure communications between the computer and other Internet-connected computing devices

II only

A gaming company is putting together a gaming tournament called GameCon. Some of the competitions will be with players outside of the conference, so the organizers want to make sure their connection to the Internet is reliable. The organizers partner with three Internet providers (Veryzone, BD&D, and InfiniX). This diagram illustrates their connection to the Internet: Each circle is a router, each line is a connection, and the lines with arrows indicate connections to further routers on the Internet. Unfortunately, this network is not fault tolerant: there's still a single point of failure. Which router needs to stay available for GameCon devices to have a working connection to the Internet?

Router B

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?

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.

Threadless is an online store that sells shirts with user-submitted designs. Anyone can register and submit a design, then community members score the designs submitted each week, and Threadless picks the top designs to sell in their store each week. Designers receive royalties for every shirt sold. Here's one example of a submitted user design: What situation would be least likely to threaten the success of the Threadless crowdsourcing model?

If a large number of new designers suddenly join the community and submit double the number of designs.

Josiah used a tool to measure how many bits he could transfer over his home connection to the Internet. This table shows the bits transferred each second: According to those measurements, what is the bandwidth of the connection?

1100 bits/s

Kiara used a tool to measure how many bits she could transfer over her office Internet connection. This table shows the kilobits transferred each second: According to those measurements, what is the bandwidth of the connection?

880 kilobits/s

Bett sends an instant message to her friend Mielle over the internet. Their computers use the TCP/IP protocols to communicate. What's the best description of how Bett's computer sends the message?

Bett's computer splits the message into packets. It does a three-way handshake with Mielle's computer to establish the connection, then sends each packet to Mielle's home router. If Bett's computer detects packet loss, it re-sends the missing packets.

The IPv6 protocol is the most recent version of the Internet Protocol (IP). IPv6 includes several new features related to both addressing and routing. Which of the following features of IPv6 most directly increases the scalability of the Internet?

Each IPv6 address is a 128-bit number. That means there are 2^{128}21282, start superscript, 128, end superscript (3.4 \times 10^{38}3.4×10383, point, 4, times, 10, start superscript, 38, end superscript) possible addresses for Internet-connected computing devices.

How often is the Internet Protocol (IP) used in Internet communications?

It is used whenever two computing devices communicate with each other over the Internet.

A 2018 survey of South African households found that only 10.4% of households have Internet access and 21.5% have a computer. Which of these would be the least effective way to reduce the digital divide across households?

Providing free subscriptions to an online video courses about digital literacy

How does the Internet Protocol (IP) fit into the Internet technology suite?

The Internet Protocol is a protocol used in all Internet communication, but other protocols are also used.

What is the relationship between the Internet and the World Wide Web?

The World Wide Web is built on top of the Internet.

The following chart displays the average bandwidth per Internet user in four island nations in 2016. Which statement is true based on this chart?

The average Internet connection in Japan can transfer more bits per second than the average connection in the Philippines.

Which of the following statements about IP addresses is true?

When data is sent between devices on the Internet, they identify each other with an IP address.

Makayla used a tool to measure how many bits she could transfer over her classroom's Internet connection. This table shows the bits transferred each second: According to those measurements, what is the bandwidth of the connection?

5500 bits/s

What does it mean for a system to be scalable?

A scalable system can handle an increasing number of users.

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?

If the Internet went down, the World Wide Web would also go down, since the WWW relies on the Internet protocols.

Which description of Internet communication is accurate?

Internet communications are powered by many protocols. One of the most important protocols is the Internet Protocol (IP) since it describes both addressing and routing. Other protocols add layers of functionality on top of that protocol, such as TCP for reliable transmission.

In 2015, the nation of Burundi had an average bandwidth per Internet connection of 11.24 kb/s. In 2016, their average bandwidth was 6.91 kb/s. Which statement is true based on those statistics?

Internet connections in Burundi in 2015 were able to transfer more bits per second than connections in Burundi in 2016.

A startup creates a website called SpeakerMeter which is designed for use at conferences. SpeakerMeter enables conference attendees to continuously rate speakers as they are speaking, so that speakers can see how much attendees like the different parts of their talks. Which of these situations would reveal the most about SpeakerMeter's scalability?

Using it for a conference with 10,000 attendees

Which diagram best represents the relationship between the Internet and the World Wide Web?

internet bigger than the world wide web lowkey looks like an egg

NSFNET was a computer network from the 1980s that connected the computer science departments of universities. In 1986, NSFNET connected 6 departments across the US: Diagram of 6 routers in a network, with 7 lines connecting them. No lines have arrows on them. Line goes from San Diego to Illinois. Line goes from San Diego to NCAR. Line goes from Illinois to Pittsburgh. Line goes from NCAR to Cornell. Line goes from NCAR to Illinois. Line goes from Pittsburgh to JVNC. Line goes from Cornell to JVNC. Redundancy in a network makes it more fault-tolerant. When two computers in a network are connected by multiple routes, that adds redundancy. How many routes are between San Diego and Cornell?

4 routes

Which of the following best illustrates inequity caused by the digital divide?

A community college student does their homework in the waiting room of a local hospital because they don't have Wi-Fi at home.

Be My Eyes is a free app for visually impaired people to get help seeing the world. When a user needs visual assistance, they can be quickly connected to a sighted volunteer from a network of a few million volunteers. Here are some examples of questions that volunteers can help answer: What situation would be least likely to negatively affect the usefulness of the app?

A huge number of volunteers sign up to be the sighted volunteers, and there are more volunteers than people that need help.

Computer A wants to send data to Computer B using the TCP/IP protocols. What's the best description of how Computer A sends the data?

Computer A splits the data into packets. It does a three-way handshake with Computer B to establish the connection, then sends each packet to the nearest router. If it detects packet loss, it re-sends the missing packets.

Which statements are true about computing devices? \text{I}Istart text, I, end text. All computing devices are able to run computer programs. \text{II}IIstart text, I, I, end text. All computing devices are capable of being interconnected to form computer networks. \text{III}IIIstart text, I, I, I, end text. All computing devices have ways to store data for later use.

I only

What is a benefit of online collaborative software?

It allows for groups to work together even if they are not in the same geographic location.

Which of these is a way that the Internet Protocol (IP) contributes to Internet communications?

It describes an addressing scheme to uniquely identify each node on the Internet./ It describes how to route packets of data around the Internet, from router to router, based on a destination address./ It describes a way to uniquely identify computing devices that are connected to the Internet so that messages can be sent to them.

Each IP packet contains a destination address. What is the primary purpose of the destination address?

It helps the router know where to send the packet.

In what situations is the Internet Protocol (IP) used?

It is used every time that two computing devices send data to each other over the Internet.

The following chart displays the average bandwidth per Internet user in four South American countries in 2016. Which statement is true based on this chart?

On average, Internet users in Uruguay are able to send more bits per second than users in Brazil.

A new high school is built and needs to be connected to the Internet. The IT administrator found these four local providers for Internet services: Which of these comparisons between the providers is correct?

SpectralWeb can transfer 2 times more data per second than TopSat.

Logan typed this URL in his browser's address bar: Which of these protocols were used by the browser in fetching and loading the webpage? 👁️Note that there may be multiple answers to this question. Choose all answers that

TCP IP HTTP

Kira sends an email message to a teammate about a conflict she's having with their boss. They later discover that the boss found out about the contents of the message. What's the most likely way that happened?

The teammate forwarded the message to the boss.

Which statement is true about packet loss on the Internet?

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.

A team of songwriters is working on song lyrics together for a pop star. They're trying to decide between two ways of working: Working on documents in a desktop text editing application and emailing their latest version of the document after editing them. Using an online collaborative text editor with real-time updates and revision history. Which of these is a benefit of using the online collaborative text editor?

With the online collaborative text editor, they can iterate more quickly on the lyrics and even edit at the same time.

Which of these configurations does NOT represent a computer network of six devices? The blue rectangles indicate devices and the green lines indicate a communication path between the devices.

one that is not attached so it lowkey looks like a sandwhich

There are some times of the year where online shoppers make significantly more purchases. One of those times is Cyber Monday, the Monday after the US Thanksgiving holiday. Large shopping websites may prepare in advance to make sure their infrastructure is scalable to handle Cyber Monday shoppers. Assuming a store where approximately 50% of shoppers make a purchase, which of these charts represent an online store that scales well to meet the demand of a surge of shoppers? The purple line shows all the shoppers on the website, while the green dashed line shows the number of sales.

purple going up green also just going up

To celebrate National Teacher Day, a social media user starts a #MyFavTeacher hashtag and encourages other users to say thank you to their favorite teacher. The FBI is concerned about the trend and whether users will accidentally reveal information that can be used to answer bank account security questions. Which tweet would be the least concerning to the FBI?

"A big thanks to my third grade teacher! They got me started down the path of science experiments. #MyFavTeacher"

The following table compares two data transport protocols from the suite of protocols powering the Internet. What are the most likely identities of Protocol 1 and Protocol 2?

Protocol 1 = TCP, Protocol 2 = UDP

Devon navigates to "https://www.orbis.org/en/where-we-work" in his browser and sees this webpage: The webpage includes a logo, map graphics, interactive map pop-ups, and a custom font. Which of these resources are loaded using the Hypertext Transfer Protocol? 👁️Note that there may be multiple answers to this question.

The custom font file The JavaScript code for the map pop-ups Each graphic file The HTML of the webpage The logo

A novelist is writing a new book. Her new editor asks her to use an online collaborative document editor to draft the book. She has some privacy concerns, however. Which of her privacy concerns are the most valid? 👁️Note that there are 2 answers to this question.

The editor can see how much time she spends writing in the document. The editor can see her typos and earlier drafts of the document.

DreamLab is a research project with a goal of coming up with better treatments for cancer patients. How it works: Anyone can download the DreamLab app onto their smartphone. The app will run computer simulations while their smartphone charges at night. The app send results back to the research team. What is the primary benefit of enabling people to run the simulations on their smartphone?

The researchers do not have to pay for the computing power used by the smartphones.

According to the Internet Protocol (IP), messages should be split into packets before being sent over the Internet. One problem with splitting the message into packets is that they might arrive out of order. TCP is a protocol that can deal with out-of-order packets. This diagram shows the structure of a packet when using TCP/IP: The IP header and TCP header both contain multiple pieces of metadata. Which part of the packet contains the sequencing information that's used by TCP to reassemble packet

TCP header

In 2013, Chicago entrepreneurs released a mobile application called Crowdfynd. People who lost items could post information on the application (description, photo, approximate location), and other people could post any items they found. Which scenario would be least likely to threaten the usefulness of the crowdfinding application?

If some users of the application were people who just wanted to see what items were lost and found.

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?

Each IPv4 address is a 323232-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).

Which of the following least illustrates inequity caused by the digital divide?

On social media networks like Twitter, many celebrities have more followers than people who are less well known./ Which of the following least illustrates inequity caused by the digital divide?

The following illustration represents a computer network: What is indicated by the lines between the computing devices in this illustration?

The computing devices are able to send messages to each other.

Jolene navigates to "https://www.nationaltrust.org.uk/" in her browser and sees this front page: The website includes a logo, photos, an interactive slideshow, and a custom font. Which of these resources are loaded using the Hypertext Transfer Protocol? 👁️Note that there may be multiple answers to this question.

The logo The slideshow JavaScript library The custom font file Each image file The HTML of the webpage

Which of the following is the best description of how routing works on the Internet?

A computer stores the destination IP address in the IP packet header and sends the packet to the nearest router. The router looks at the IP address and decides where to send the packet next based on a lookup table. The next router does the same, until the packet finally ends up at its destination.

Which of these situations describes a computer network?

A video gaming club sets up six powerful computers in a room and connects them with Ethernet cables to a router. The club members play multi-player games together./ A company gives every employee a desktop computer and connects each of the computers to each other using wires, so that they can quickly transfer files and messages.

The following is an incomplete diagram representing the World Wide Web: What would be the most accurate icon to replace the question mark?

An icon of a webpage

Computer A wants to send data to Computer B using the TCP/IP protocols. What's the best description of how Computer A sends the data?

Computer A splits the data into packets. It does a three-way handshake with Computer B to establish the connection, then sends each packet to the nearest router. If it detects packet loss, it re-sends the missing packets.

Which of these is an accurate description of how the TCP/IP protocols send data around the internet?

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.

Which statement is true about computing devices in a computer network?

Each computing device must be able to send data to the other computing devices.

The Internet Protocol (IP) includes a rule that each message must include a source IP address and a destination IP address. What are the likely consequences of a computer sending a message that does not follow that IP rule? \text{I}Istart text, I, end text. The computer will be put on a blocklist and not permitted to send future messages over the Internet for a period of time. \text{II}IIstart text, I, I, end text. The message might not travel over the Internet or arrive at its destination at all. \text{III}IIIstart text, I, I, I, end text. The message will still travel over the Internet but the contents of the message will be censored.

II only

Aisha sends an email message to her classmate Jamarion asking him to the prom. Which of these actions can Jamarion do without the consent of Aisha? 👁️Note that there may be multiple answers to this question.

Reply to the message with another classmate CC'ed Forward the message to another classmate Take a screenshot of the message Replying to the message with another classmate BCC'ed

A new Internet provider ZoomyZoomy is creating advertising that focuses on the bandwidth of their connections. Which of these slogans has the correct unit? Choose 1 answer:Choose 1 answer:

Sign up now for a bandwidth of 50 megabits/second!

Which of these situations describes the creation of a computer network?

A college campus creates multiple computer labs in different parts of the campus and connects the labs to each other with underground fiber optic cables. Students can save their file on a computer in one lab and still access their files from another lab.

In April 2020, Twitter users started a trend of posting their high school graduation photos. The FBI issued a warning soon after about the risks of posting those photos on public social media accounts. Which of these is not a potential risk of posting an old graduation photo?

An attacker could download the image and threaten to share it with the press unless the user gives them money.

Yuto posts a tweet on his Twitter account with a photo of himself taking a bubble bath. A few months later, while preparing for a job interview, he decides to delete the photo in case the job recruiters find it. Once Yuto deletes the tweet, can the recruiters find the photo?

Yes, if the tweet was archived by a web archive service or uploaded elsewhere by others who saw it.

Which of the following aspects of the Internet has most increased its scalability?

Any computing device can connect to the Internet as long as it follows the open Internet protocols.

Which of these are a requirement for a computer to access the Internet? \text{I}Istart text, I, end text. A wired connection using either an Ethernet or Fiber optic cable \text{II}IIstart text, I, I, end text. A monthly payment to the Internet Engineering Task Force \text{III}IIIstart text, I, I, I, end text. The ability to connect that computer to another Internet-connected device

III only

Which of these situations describes the invention of a networking protocol?

Leighton proposes a set of rules that describe a way for computers to send data on low-bandwidth connections and lists them in a document. Multiple network administrators agree to the rules and implement them.

The One Million Masterpiece is a global art project with the goal of collecting tiny digital pictures from online contributors and stitching them together into a giant canvas. Which of these is most likely true about the contributed pictures to the project?

There will be a variety in what the pictures look like.

Which of the following is the best description of an IP address?

A number that identifies Internet-connected devices/ A number assigned to a computing device that can receive data on the Internet

In 2019, the Pew Research Center surveyed Americans about their household's access to computers and the Internet. This chart shows the percentage who reported having access to a broadband Internet connection from 2000 - 2019, categorized as either "urban", "suburban", or "rural": Which of these would be the most effective way for the American government to reduce the digital divide demonstrated above, between rural households and suburban/urban households?

A partnership with an Internet carrier to install broadband Internet infrastructure in rural areas and provide household access at discounted rates.

Bharat runs a computer room at a library. The room has a variety of Internet-connected devices: 20 desktop computers (connected via Ethernet) A 3-d printer (connected via wireless) A security camera (connected via Ethernet) Which of those devices use the Internet Protocol (IP) when sending data through the Internet?

All of them (the desktop computers, 3-d printer, and security camera)

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?

Each router can pick a connection that's currently working and available.

Which of these statements about the digital divide is true?

Even for-profit companies can take actions to help bridge the digital divide.

In 2015, programmer Brendon Ferris created a website to crowdsource a melody. Visitors could vote for the next note in the melody's sequence, and once there were enough votes, the website would store the top-voted note. Which of these is true about his decision to crowdsource a melody?

He could not predict at the start of the project how the final melody would sound.

Which of these statements about the Internet Protocol (IP) are true? \text{I}Istart text, I, end text. It is the only protocol used in Internet communications. \text{II}IIstart text, I, I, end text. It is used every time a computing device sends a message over the Internet. \text{III}IIIstart text, I, I, I, end text. It is one of many protocols used on the Internet.

II & III only

The Internet Protocol (IP) includes a rule that each message must include a source IP address and a destination IP address. What are the likely consequences of a computer sending a message that does not follow that IP rule? \text{I}Istart text, I, end text. The administrator of the device will receive a message from the Internet Protocol Authority (IPA) reminding them of the proper addressing format. \text{II}IIstart text, I, I, end text. The message will arrive at its destination more slowly since it will be forced to travel along slower network connections for violating the rules. \text{III}IIIstart text, I, I, I, end text. The message may not arrive at its destination at all.

III only

Ororo typed this URL in her browser's address bar: https://www.nssl.noaa.gov/ After a few seconds, the browser loaded the webpage: Which of these protocols were used by the browser in fetching and loading the webpage? 👁️Note that there may be multiple answers to this question.

IP HTTP TCP

Logan typed this URL in his browser's address bar: http://wolverinefoundation.org/ After a few seconds, the browser loaded the webpage: Which of these protocols were used by the browser in fetching and loading the webpage? 👁️Note that there may be multiple answers to this question

IP TCP HTTP

An intranet is a private network set up for an organization like a company or university. Here's an intranet with six routers labeled A - F: Diagram with 6 routers labeled A through F and 7 lines connecting them. There are no arrows on any of the lines. Line goes from A to B Line goes from A to C Line goes from B to C Line goes from C to E Line goes from C to F Line goes from D to E Line goes from E to F An intranet is more secure, because computers can communicate without using the publicly accessible Internet, but it is often not as fault-tolerant. Imagine that router B needs to send a message to router D. Which of the following situations will lead to the message failing to arrive? 👁️Note that there are 2 answers to this question.

If these two connections go down: C to E, and F to E. If the connection between D and E goes down.

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?

It always uses multiple protocols.

Amazon describes their web services platform like this: Amazon Web Services (AWS) is a highly reliable, scalable, low-cost infrastructure platform in the cloud that powers hundreds of thousands of enterprise, start-up and public sector business with organizations in over 190 countries around the world. What does it mean for the platform to be scalable?

It continues operating when experiencing traffic surges.

A team is designing a new user interface for a website and deciding between two formats for collaboration: An in-person brainstorming session using paper, markers, and post-its A digital document in a productivity software suite that allows for simultaneous editing and comment threads What would be the benefit of collaborating with the digital document?

It would accomodate team members that could not attend the session in person.

Lavanya is a startup founder who is working on the design of a smart bracelet. She needs to sketch out some ideas with a designer who lives in another country and wants to try using an online collaborative whiteboarding program for their design session. Lavanya is nervous about their design ideas being lost or getting into the wrong hands, however. Which of these is not a way that the whiteboarding data could be lost or stolen? Choose 1 answer:Choose 1 answer:

Lavanya could accidentally drop her laptop, resulting in a damaged hard drive and erased data.

A group of researchers surveyed German Internet users to discover their amount of participation in online politics, such as signing a petition and engaging in an online political group, and their level of concern about privacy. The researchers then used statistical methods to make correlations between demographic characteristics, privacy concerns, and online political participation. Which research finding is most indicative of a digital divide in online political participation?

Men engaged more frequently in online political participation than women.

Benjamin is writing code for a medical software company. He would like feedback on his code and is considering either asking a colleague for an in-person code review or uploading the code to a collaborative code review program. What would be the most likely advantage of using collaborative code review software? Choose 1 answer:Choose 1 answer:

Multiple colleagues could see his code and give feedback on ways to improve it.

Zaniyah wants to share photos of her newborn baby on her public social media account. She wants to be able to delete the posts once her baby grows up, however. How can she ensure she can completely delete the photos off the Internet later? Choose 1 answer:

None of the above (There is no certain way to do this.)

Zooniverse is an initiative across multiple universities that runs many online citizen science projects. In the Plant Letters project, volunteers transcribe scanned images of letters to botanists at the Botanic Garden in the University of Coimbra, Portugal. Each letter is transcribed by multiple volunteers, so that mistakes made by a single volunteer won't be in the final transcription. This screenshot shows the letter transcribing interface: The university could have run this project in Portugal with local volunteers, but they chose to run it online. Which of these does not describe a benefit of running Plant Letters as an online citizen science project?

Online volunteers will generally be of a higher quality than local volunteers.

A group of organizers are putting together a conference called DevFest and want to make sure the Internet connection will be reliable. They partner with two Internet providers, Komkastic and SupaSonic. This diagram illustrates their connection to the Internet: Diagram of network. A series of laptop computers are shown on left, labeled DevFest. Two wireless signals emanate towards those laptops from two routers, labeled Komkastic and SupaSonic. The routers are connected to a network with four other routers labeled A, B, C, and D. Line connects Komkastic's router to Router D. Line connects SupaSonic's router to Router D. Line connects Router D to Router A. Line connects Router D to Router B. Line connects Router D to Router C. Routers A, B, and C have 3 arrows each coming out from them, indicating a continuing network. Each circle is a router, each line is a connection, and the lines with arrows indicate connections to further routers on the Internet. Unfortunately, this network is not fault tolerant: there's still a single point of failure. Which router needs to stay available for DevFest to have a working connection to the Internet?

Router D

A school installs four smart sensors that can detect vaping. The sensors are connected to the Internet so that district administrators can visit a password-protected website and view data in real-time. The administrator can also send a command to a sensor to trigger an alarm mode. According to the Internet Protocol (IP), each sensor must have a unique identifier so that it can send and receive data over the Internet. Which table shows identifiers that could be used by IP to identify the sensors?

SensorIdentifierSensor 1241.36.170.245Sensor 280.12.159.104Sensor 346.84.179.85Sensor 4203.218.117.190

Aliana just moved into a new home and needs to choose an Internet provider. She researched local providers and found these four: How much data can be transferred over ConnectPlus as compared to SuperSonic?

The ConnectPlus connection can transfer 10\%10%10, percent the amount of data per second.

Fen navigates to "https://www.conservationfund.org/" in her browser and sees this on the front page: The front page includes a logo, photos, a video, an interactive slideshow, and a custom font. Which of these resources are loaded using the Hypertext Transfer Protocol? 👁️Note that there may be multiple answers to this question.

The HTML of the webpage Each photo file The JavaScript code for the slideshow The custom font file The video file The logo file

The Griffin family lives in multiple states, so they decide to use an online collaborative website to create their annual photo book. The website lets each of them upload photos from their computer, and then they can all arrange the photos into pages. What valid privacy concerns might the family members have? 👁️Note that there are 2 answers to this question.

The company that created the website now has a copy of the family's personal photos on their web servers. One of the family members could accidentally upload a photo that others did not want to be shared.

Lavanya is shopping for her first house. At an open house, a real estate agent calls the house a "smart home" and explains that all of the home appliances are also computing devices that are connected together in a computer network. What is the benefit of networking the devices together?

The computing devices can transfer data to each other.

Globe at Night is an international citizen science project with the goal of measuring the night sky brightness and understanding the impact of light pollution. Volunteers report the night sky brightness using an online interface: This map visualizes the 8,069 observations recorded in 2018: Which of these is not a benefit of running this as a citizen science project?

The observations recorded by volunteers will be higher quality than observations recorded by professional astronomers.

The privacy policy for Twitter starts with this paragraph: Twitter is public and Tweets are immediately viewable and searchable by anyone around the world. We give you non-public ways to communicate on Twitter too, through protected Tweets and Direct Messages. You can also use Twitter under a pseudonym if you prefer not to use your name. This is a screenshot of the privacy settings for a particular user: Based on the policy and that setting, what is true about the user's tweets?

Their tweets are not publicly viewable.

Which of these best describes the fault tolerance of routing on the Internet?

There are multiple routes for each IP packet to follow. A packet can be re-routed if a path becomes unavailable.

In 2015, researcher Teresa Correa studied social media use in a sample of 18 to 29 year olds in Chile. She was interested in this age group as they are often called "digital natives," the youth that grew up around computers and the Internet, and she wanted to understand the differences in digital skills amongst them. Which of the following research findings describe a digital divide? 👁️Note that there are 2 answers to this question.

There was a positive correlation between education levels and digital skills. There was a significant difference between the level of digital skills between the men and women in the sample.

The following passage describes the Internet but contains a missing adjective: The Internet is built on a stack of communication protocols that are standardized and <???> . As a result, any computer can communicate with other computers on the Internet, without needing to apply for a license from a company. What is the most appropriate adjective to replace <???>?

nonproprietary

Which diagram best illustrates the process of routing a single packet from a sender to a receiver on the Internet?

one with the arrow pointing to the bottom row and stays on the bottom row then goes up and down to the computer.

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 <???>?

open

Consider the following statement: The World Wide Web is a web connecting billions of <NOUNS>. What would be the most accurate replacement for <NOUNS>?

webpages

The Internet Protocol (IP) describes how packets can be sent from a sender to a receiver. First, the sender creates an IP packet with the destination IP address in the packet header. Which of these sequences correctly describe the next steps in routing that packet?

1. The sender sends the packet to the nearest router. 2. The router looks in a forwarding table to find a router that will get the packet closer to its destination and sends the packet to that router. 3. Each subsequent router uses their forwarding table to pick the next router.

Startuppr is a web company that's running their servers out of their garage. Their network administrator is tasked with determining if there is a single point of failure in the network—a router whose outage could cause their servers to lose connection to the Internet. The administrator analyzes this partial diagram of the network: Diagram of network. A series of computers labeled StartUppr are shown on left. The computers are connected two a central line that connects to a series of routers labeled A, B, C, D, E, and F. Line connects StartUppr computers to router A. Line connects router A to router B. Line connects router A to router C. Line connects router B to router E. Line connects router C to router E. Line connects router E to router D. Line connects router E to router F. Routers D and F have 3 arrows each coming out from them, indicating a continuing network. Each circle is a router, each line is a connection, and the lines with arrows indicate connections to further routers on the Internet. How many single points of failure would the network administrator find?

2

Which of these addresses is the kind used by the Internet Protocol (IP) to identify devices that are connected to the Internet?

242.185.95.235

NSFNET was a computer network from the 1980s that connected the computer science departments of universities. In 1986, NSFNET connected 6 departments across the US: Redundancy in a network makes it more fault-tolerant. When two computers in a network are connected by multiple routes, that adds redundancy. How many routes are there between San Diego and Illinois?

3 routes

NSFNET was a computer network from the 1980s that connected the computer science departments of universities. In 1986, NSFNET connected 6 departments across the US: Diagram of 6 routers in a network, with 7 lines connecting them. No lines have arrows on them. Line goes from San Diego to Illinois. Line goes from San Diego to NCAR. Line goes from Illinois to Pittsburgh. Line goes from NCAR to Cornell. Line goes from NCAR to Illinois. Line goes from Pittsburgh to JVNC. Line goes from Cornell to JVNC. Redundancy in a network makes it more fault-tolerant. When two computers in a network are connected by multiple routes, that adds redundancy. How many routes are there between San Diego and Illinois?

3 routes

A 2016 report found these statistics for citizens of Bolivia: Which of these would be the most effective way to reduce the digital divide between the urban and rural households?

A program that donates refurbished laptops to residents of rural villages.

Max decides to work with a tax accountant on putting together his taxes, since he finds it overwhelming to do all the paperwork himself. The accountant suggests using an online collaborative spreadsheet program to collect all the information necessary. Max is concerned that his tax information may get lost or stolen, however. Which of these is not a way that the tax information in the spreadsheet may get lost or stolen?

Max's partner could borrow his laptop and accidentally delete the tax information from the hard drive.

A student used a tool to track the route taken by an IP packet from a library computer to the IP address of the Code.org server. According to the tool, this is the route the packets took: If they run the tool again (but still with the destination IP address for Code.org), in what way could the next packet's path be different?

It could take a different amount of time to get to each stop. It could stop at more routers along the way. It could stop at fewer routers along the way. It could stop at different routers along the way.

There was a significant difference between the level of digital skills between the men and women in the sample.

It is used whenever two computing devices send data to each other over the Internet.

When do Internet-connected computing devices use the Internet Protocol (IP)?

It is used whenever two computing devices send data to each other over the Internet.

For a project called "The Sheep Market", Aaron Koblin collected drawings of sheep from strangers on the Internet. He posted the task on the Amazon Mechanical Turk crowdsourcing platform for 2 cents, and over the course of 40 days, at a rate of about 11 sheep per hour, he collected 10,000 drawings from 7,599 IP addresses. Which of these is true about his decision to crowdsource the sheep drawings?

Aaron could expect diversity in the style of the sheep drawings.

A gardener sets up a network for a garden using a variety of devices: A smart temperature sensor: It runs a program that checks whether the temperature is above or below the target range for that time of day and then triggers the heating or cooling system when needed. A security camera: It uses a machine learning algorithm to detect non-plant motion and sends video footage to a computer. A desktop computer: It generates a graph of the temperature based on data from the temperature sensor and stores video footage from the camera. A wireless router: It uses networking software to enable the sensor, computer, and camera to send data to each other. Which of the devices in the network are considered computing devices?

All of them (the computer, router, camera, and sensor)

In 2015, researchers Eszter Hargittai and Aaron Shaw surveyed college students to understand the differences between the students that had contributed to Wikipedia and those that hadn't. The surveys asked for their demographic information, their self-rating of Internet skills levels, and their experiences with contributing to Wikipedia. The researchers then analyzed the survey results and used statistical analysis to discover the relationships between demographics, Internet skills, and Wikipedia contributions. Which of the following research findings are not indicative of a digital divide? 👁️Note that there are 2 answers to this question.

Asian American and African American respondents were equally likely to have made contributions to Wikipedia. Socioeconomic status was not a significant predictor of whether a respondent had contributed to Wikipedia.

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 <???>?

Open

Bria used a tool to track the route taken by an IP packet from her laptop to the IP address of the Google.com server. According to the tool, this is the route the packets took: If she runs the tool again to trace the route of a packet to Google.com, what are the possible outputs? \text{I}Istart text, I, end text. The same sequence of stops \text{II}IIstart text, I, I, end text. The same number of stops, but different IP addresses. \text{III}IIIstart text, I, I, I, end text. A shorter sequence of stops. \text{IV}IVstart text, I, V, end text. A longer sequence of stops.

I, II, III, or IV

In what situations does a computer use multiple Internet protocols to send a message? \text{I}Istart text, I, end text. When it sends an encrypted message \text{II}IIstart text, I, I, end text. When it wants an acknowledgement that the destination computer received the message \text{III}IIIstart text, I, I, I, end text. When it is loading webpage data

I, II, and III

Which of the following kinds of computing devices use the Internet Protocol (IP) when sending data over the Internet? \text{I}Istart text, I, end text. A tablet computer \text{II}IIstart text, I, I, end text. A desktop computer \text{III}IIIstart text, I, I, I, end text. A smartphone

I, II, and III

Ororo typed this URL in her browser's address bar: https://www.nssl.noaa.gov/ After a few seconds, the browser loaded the webpage: Which of these protocols were used by the browser in fetching and loading the webpage? 👁️Note that there may be multiple answers to this question.

IP TCP TCP

The following is a diagram of two computers exchanging information over the Internet. The diagram is incomplete, however, as it is missing identifiers for each computer. According to the Internet Protocol (IP), what would be appropriate identifiers to replace <Identifier A> and <Identifier B> in the diagram?

IdentifierValue<Identifier A>122.69.249.117<Identifier B>234.33.12.64

An intranet is a private network set up for an organization like a company or university. Here's an intranet with five routers labeled A - E: Diagram with 5 routers labeled A through E and six lines connecting them. There are no arrows on any of the lines. Line goes from A to B Line goes from B to C Line goes from C to E Line goes from A to D Line goes from D to B Line goes from D to E An intranet is more secure, because computers can communicate without using the publicly accessible Internet, but it is often not as fault-tolerant. Imagine that router A needs to send a message to router E. What situations will lead to the message failing to arrive? 👁️Note that there are 2 answers to this question.

If these 2 connections go down: B to C, and D to E. If these 2 connections go down: D to E, and C to E.

An intranet is a private network set up for an organization like a company or university. Here's an intranet with five routers labeled A - E: Diagram with 5 routers labeled A through E and 6 lines connecting them. There are no arrows on any of the lines. Line goes from A to B Line goes from A to D Line goes from B to C Line goes from B to D Line goes from C to D Line goes from D to E An intranet is more secure, because computers can communicate without using the publicly accessible Internet, but it is often not as fault-tolerant. Imagine that router C needs to send a message to router E. Which of these situations will lead to the message failing to arrive? 👁️Note that there are 2 answers to this question.

If these two connections go down: B to C, C to D. If the connection between D and E goes down.

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>?

Kilobits per second

A startup creates a chatbot that uses artificial intelligence algorithms to have therapeutic conversations with users. Which of these decisions would most directly reveal the most about the chatbot's scalability?

Launching the chatbot in multiple platforms (Android, iOS, and Facebook) on the same day

Lavanya is a startup founder who is working on the design of a smart bracelet. She needs to sketch out some ideas with a designer who lives in another country and wants to try using an online collaborative whiteboarding program for their design session. Lavanya is nervous about their design ideas being lost or getting into the wrong hands, however. Which of these is not a way that the whiteboarding data could be lost or stolen?

Lavanya could accidentally drop her laptop, resulting in a damaged hard drive and erased data.

Rafi is developing an application to send urgent information about global health crises over the Internet to hospitals. He is worried about packets getting lost along the way and the effect that will have on the accuracy of the information. What is his best option for dealing with lost packets?

Rafi can use the Transmission Control Protocol for communication, since TCP has ways to recover when packets are lost.

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?

Routers look at the IP packet header and use the destination address field.

Why does each IP packet contain a destination address?

Routers use the destination address to decide where to send a packet next.

Eloise wants to share her political views with family members living in another state but doesn't want her posts to be viewed by potential employers in the future. What is the best strategy for ensuring that?

She can send email messages with family members CC'ed on the email thread.

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 IP packet contains a TCP segment with metadata and data. Which part of the packet contains the sequencing information that's used by TCP to reassemble packets?

TCP metadata

A company moved into a new office space and needs to sign up with an Internet provider. They found these four local providers for business Internet services: How do the ComSat and BroadbandUp connections compare?

The BroadbandUp connection can transfer four times the amount of data per 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?

The TCP metadata includes fields that describe where the packet belongs in the sequence.

A computer must adhere to the Internet protocols in order to send data through the Internet. Which of these best describe what it means for a computer to adhere to a protocol?

The computer must send data according to the documented rules of the protocol.

The TV show Silicon Valley revolved around a startup and their attempt to bring a new product to market. At one point, the creators of the startup say this about their product: "We're making the world a better place through scalable fault-tolerant distributed databases." What does it mean for the databases to be scalable?

They can continue functioning even if there is a significant increase in the number of operations they must perform.

What is the job of a router during the process of routing on the Internet?

The router's job is to look up the destination IP address in their forwarding table, determine the next router that will get the packet closer to its destination, and send the packet to the router.

ClimatePrediction is a volunteer computing project with the goal of understanding how climate change is affecting the world currently and how it may affect it in the future. Once volunteers sign up for the project and download the application, their computer will run climate models whenever it has spare CPU cycles. The data generated by the climate models are sent back to the project's central database and scientists use the results in their research. What's the primary benefit of enabling volunteers to run the climate models on their home computers?

The researchers do not have to pay for the computing power used by the home computers.

Over the years, engineers have invented many networking technologies for LANs (local area networks). The chart below visualizes the bandwidth of 4 different LAN technologies. The x-axis of the chart represents the bandwidth, but it has no unit. Which unit is the most appropriate unit to describe the bandwidth axis?

Gigabits per second

The goal of the MilkyWay@Home volunteer computing project is to build an accurate model of the Milky Way by simulating the composition of dark matter around the galaxy. Once volunteers sign up for the project and download the application, their computer will run models of the galaxy whenever it has spare CPU cycles. The results are sent back to the project's central database, so that scientists can identify the models with the best fit and publish the results. What's the primary benefit of enabling volunteers to run the models on their home computers?

The researchers do not have to pay for the computing power used by the home computers.

This diagram illustrates a wireless network made up of five devices: an Apple iPhone, an Android phone, a desktop computer, a tablet computer, and a wireless router. Why are those devices considered computing devices?

They are capable of running computer programs.

The US postal service can serve as an analogy for Internet transport protocols. The postal service offers various services: First class letter: the default service with no extras. Certified mail: sent using the standard route but provides the sender with proof that the letter was delivered. Registered mail: sent using secure mechanisms along the way (e.g. locked cages). Similarly, there are multiple transport protocols that can be used on top of IP, with TCP and UDP being the most popular. Which analogy between the transport protocols and USPS services makes the most sense?

UDP is like the first class letter service and TCP is like the certified mail service.