APCSP Unit 2
Which best describes the subdomain of a URL?
(B) The subdomain appears immediately to the left of second-level domain and is period (.) delimited.
Protocol
A set of rules governing the exchange or transmission between devices.
Abstraction
A way to reduce the complexity of a program by hiding all but the relevant data.
A hierarchy is a system of classifying items in different levels relative to each other. Which one of the following systems does NOT function in a hierarchical arrangement?
An iteration performed in an Algorithm
With the advent of telemedicine, the doctors in the International Hospital are eager to provide the much needed medical assistance to patients in remote areas. To ensure that doctors are able maintain their connections to their remote patients without any interruptions, the network system in the hospital must :
Be redundant
What is a disadvantage of the open standard of Internet addressing and routing? Select two answers.
Censorship Possibility of denial of service attacks
Router
Computer that receives messages travelling across a network and redirects them towards their intended destination based on the addressing information included in the message.
When a message is sent across the internet using the TCP/IP protocol it is sent using network packets. Which of the following does each network packet contain? Select two answers.
Control information for routing the data A small portion of the message
Which of the following is NOT a true statement about devices and the Internet?
Devices are limited to communicating over the Internet with only other devices within the same local area.
RFC (Request for Comments)
Documents that show how standards and protocols are defined and published for all to see on the IETF website.
HTTP requests and responses have identical formats.
False
Information travelling between two computers over the Internet will always take the same path.
False
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
False
TCP depends on the infrastructure of the Internet to be reliable enough to ensure no packets are lost in transmission
False
A major connection in a network is damaged so that information can no longer be sent through the connection. If full communication on the network was able to continue, which of the following characteristics would the network be said to have?
Fault-tolerant (or redundant) routing Clear selection
The IETF (Internet Engineering Task Force) is responsible for developing and overseeing internet standards. Which of the following is not a common protocol maintained by the IETF?
GPS
What is the primary application protocol used by the World Wide Web for delivering web content?
HTTP
Why is HTTP is considered to be a high level protocol?
HTTP requests make use of abstractions provided by lower level protocols.
Select the benefits of HTTPS protocol
HTTPS verifies the identity of the server through a Certificate Exchange HTTPS provides reasonable assurance by which the user can assume minimal cybersecurity risk of transactions carried out on that site.
What feature of DNS and IP allow the internet to scale?
Hierarchal design
Differences between Ipv4 and Ipv6
IPv4 has 32 bits 2^32 = about 4 billion addresses uses binary IPv6 has 128 bits 2^128 = about 340 undecillion uses hexadecimal
Internet Protocol version 4 (IPV4) uses a 32 bit binary number to represent an IP address. Internet Protocol version 6 (IPv6 ) uses a 128 bit binary number to represent the same. Which one of the following BEST describes the reason for this changeover in IP address representation?
IPv6 allows for 296 times more IP addresses. This will ensure that we will have enough IP addresses to address the exponential demand for IP addresses in the future.
What does it mean for the routing of the Internet to be fault tolerant and redundant?
If one path for data transmission is blocked or corrupted, data can follow another path.
This diagram shows a number of computing devices connected to the Internet with each line representing a direct connection. Device A is attempting to send data over the Internet to Device E. Which of the following is true of how the data will travel through the network?
It is possible that the data travels through any of the devices in the network before arriving at device E
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 functionality to high level protocols without revealing the details of how this is accomplished.
IP Address (Internet Protocol Address)
Number assigned to any item that is connected to the internet
The Internet is a packet-switched system through which digital data is sent by breaking data into packets which contain both the data being transmitted and the control information for routing the data. Which one of the following statements is an accurate statement about packet-switching?
Packets from the sending device can take different routes to reach the same destination device.
The Internet is a packet-switched system through which digital data is sent by breaking data into packets which contain both the data being transmitted and the control information for routing the data. Which one of the following statements is an accurate statement about packet-switching
Packets from the sending device can take different routes to reach the same destination device.
Which of the following is MOST likely to be an outcome of the digital divide?
People from some racial or ethnic groups have unequal access to computing technology.
End-to-end architecture
Processing of Internet traffic is done at the sending and receiving locations
HTTP (HyperText Transfer Protocol)
Protocol used by World Wide Web. It describes how messages are formatted and interchanged and how web servers respond to commands.
Email communication standard developed and overseen by the Internet Engineering Task Force.
SMTP protocol
Packets
Small chunks of information that have been carefully formed from larger chunks of information.
Why do computers need to periodically check the DNS for websites you have already visited?
The IP address associated with a given URL is not static; it can change.
Who defines the protocols and standards for how the Internet works?
The Internet Engineering Task Force (IETF). The members of the IETF are a loosely organized collection of citizens and engineers who communicate mostly by email.
What is bandwidth?
The amount of data that can be transmitted in a specified amount of time.
DNS (Domain Name System)
The internet's system for converting alphabetic names into numeric IP Addresses
What is Secure Sockets Layer (SSL)
The standard security technology for establishing an encrypted link between a web server and a browser, typically indicated with padlock icon in the address bar
The Internet Engineering Task Force is a large open international community of network designers. What is the primary role of the Internet Engineering Task Force (IETF)?
To provide long-range technical direction for and address issues related to Internet protocols, applications, architecture, standards, and technology.
A HTTP request is sent from a client to request access to data stored on a server.
True
A packet contains addressing information to allow routers to decide how best to forward along that packet towards its destination.
True
A packet traveling between two computers on the Internet may be rerouted many times along the way
True
Displaying a web page will often require multiple HTTP requests in order to acquire all the necessary data.
True
Packets are numbered so if they arrive out of order the message can be reassembled
True
TCP ensures messages can be reliably transmitted across the Internet
True
TCP must account for the fact that packets may not arrive at a destination computer in the intended order
True
The receiver computer must confirm to the sending computer that each packet was received
True
What must devices that communicate with one another on the internet have in common?
Use the same internet protocols.
Why don't we need to know the IP addresses for our favorite sites?
When we type in a web page address and click [enter], the browser contacts the DNS server to look up the IP address. It does this every time we browse to a page.
The working of the Internet can be modeled by the 4 layer TCP/IP Model. Which ways does TCP, the Transport Control Protocol layer interact with the other layers of the internet?
While sending messages, the TCP layer breaks information down into packets and hands it off to the IP layer. TCP reassembles all packets received, puts it in the correct order, and transmits it to the Application layer that uses Protocols like SMTP for email, VOIP for Skype, etc.
World Wide Web
collection of web pages, or documents, written in hypertext markup language (HTML)
Which is a subdomain of computer.com?
help.computer.com
Which of the following URLs contains a domain name with a fourth-level domain?
https://about.content.example.com
Internet
interconnection of computer networks. The Internet is hard-wired driven with wires, cables, and devices such as routers and servers, with some wireless connections
UDP
protocol for sending packets quickly with minimal error-checking and no resending of dropped packets
SMTP (SMTP (Simple Mail Transfer Protocol)
protocol used to add headers to outgoing emails and direct the data from one email server to another
TCP/IP
provides reliable, controlled and error-checked delivery of a stream of packets on the internet. IP is the process by which packets move through the network to their target location.
DDos
targeted web serve is flooded with so many requests that it cannot handle them all, the web server will become very slow and ultimately crash, meaning it stops responding to all requests
Net Neutrality
the principle that all Internet traffic should be treated equally by Internet Service Providers
Fault tolerant
the redundancy built into the Internet so that traffic may be redirect if at one point it is not working
HTTPS
used for secure transaction, uses Certificate Authorities (CAs) to verify a site's identity, trades faster performance for more security
A single central register of IP addresses and names (a DNS style system) is an efficient means of translating human readable names to IP addresses. What are some of the problems solved by DNS?
• It is inefficient to have everyone on the Internet maintain their own list of IP addresses. • When someone new joins the Internet they must inform everyone else of the new IP address • When an IP address changes, it is impossible to locate a computer until the owner announces the change.
