apcsp unit 2

Top level domain

.org

internet

A group of computers and servers that are connected to each other

IP address

A number assigned to any item that is connected to the Internet.

IPv4 Packet

A packet of data that uses 32 bit addresses

protocol

A set of rules governing the exchange or transmission of data between devices.

There are too few IP addresses to meet the current demand.

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. Which of the following is NOT solved by DNS?

router

A type of computer that forwards data across a network

url

An easy-to-remember address for calling a web page (like www.code.org).

You can encode a path for your message to go on. If you know the IP address of the person you want to send the message to then you should be able to send them your message

Can you know in advance the path a message will take between you and another computer on the Internet? Justify your answer.

An HTTP request is sent from a client to request access to data stored on a server. Displaying a web page will often require multiple HTTP requests in order to acquire all the necessary data.

Choose Two: Identify the two true statements about HTTP.

make informed choices to support or oppose decisions my government makes about access to the internet. make informed choices about my privacy on the internet.

Choose the two best answers to complete the sentence: If I understand how the internet works then I will be able to:

When routing you can see who sent you a message instead of not knowing who sent you something. This shows how routing is more secure than broadcasting.

Describe the relative benefits of routing over a broadcast style of communication. Is routed traffic more secure than broadcasting? Justify your answer.

Someone could copy your name and say it was a hit when really it was a miss.

Even with a good protocol, what are some privacy and security challenges while playing battleship on the Internet Simulator?

Vint Cerf explains that the internet is for everyone but it won't be if it is restricted and governments censor access. Example include countries that lack freedom such as China, for the government restricts their citizens' internet usage.

Explain one challenge raised by Vint Cerf in "The Internet is for Everyone - but it won't be if...." and give one example of it that you know about.

HTTP requests make use of abstractions provided by lower level protocols.

HTTP is considered to be a high level protocol because:

64 users

How many unique IP addresses could be made in a fixed-length IP address system using 6 bits?

http

HyperText Transfer Protocol - the protocol used for transmitting web pages over the Internet

The mailman would sometimes take a different path to deliver each letter to your home. Letters would be written on the outside of envelopes for all to read instead of letters put inside envelopes.

If the post office delivered mail exactly like routers deliver messages on the internet, which 2 of the following statements would be true?

The first 4 bits of the address specify the router number that your friend is on.

In the Internet Simulator, your router knows to send your message to a different router because:

We need to be able to know what part of the message we are sending and we need to know how to save space because we have a limited amount of bits. We also do not want to cause traffic. Also the packets would be missing. In the internet packets are missing all the time so they just resend the ones that did not send to start with.

In your own words, what were the primary obstacles you needed to overcome in today's challenge? How do these obstacles mirror actual problems encountered on the Internet?

IETF

Internet Engineering Task Force - develops and promotes voluntary Internet standards and protocols, in particular the standards that comprise the Internet protocol suite (TCP/IP).

A packet travelling between two computers on the Internet may be rerouted many times along the way. A packet contains addressing information to allow routers to decide how best to forward along that packet towards its destination.

Letters would be written on the outside of envelopes for all to read instead of letters put inside envelopes.

TCP ensures messages can be reliably transmitted across the Internet TCP must account for the fact that packets may not arrive at a destination computer in the intended order

Pick Two: Pick the two statements about packets and routing on the Internet which are true.

pakets

Small chunks of information that have been carefully formed from larger chunks of information.

A loosely organized collection of citizens and engineers who communicate mostly by email

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

Abstraction involves removing details and generalizing functionality. ASCII codes do not need to know why or how it works, it just needs to know that it does. This applies to the protocols that make up the different functions of the Internet because each is able to assume that certain functionality already exists and doesn't need to account for its explicitly.

The definition of HTTP makes use of the ASCII character set without reference to how these characters are encoded. Explain why this is an example of abstraction.

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.

They need to constantly check the dns system for websites I have already visited because they need to make sure their are no errors with anything.

tcp

Transmission Control Protocol - provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. TCP is tightly linked with IP and usually seen as TCP/IP in writing.

hierachy

What feature of DNS and IP allow the internet to scale?

request for comments

What is an RFC?

A message sent across the Internet can always be contained in a single packet

Which of the following is NOT true about packets?

They need to constantly check the dns system for websites I have already visited because they need to make sure their are no errors with anything.

Why do computers need to periodically check the DNS for websites you have already visited?

Transmission control protocol

dns, tcp, ip, physical internet

Sub domain

donate. is an example

netowrk redundancy

having multiple backups to ensure reliability during cases of high usage or failure

The Internet Protocol (IP)

required structure of a packet to be sent to the internet

dns

short for Domain Name System, this system translates domain names (like example.com) to IP addresses (like 93.184.216.34)

Net Neutrality

the principle that all Internet traffic should be treated equally by Internet Service Providers.