Wednesday, September 12, 2018

Thursday, September 13, 2018 A partial day, an Early Release day...what fun!

QUOTABLES

Mkt - Promotion that got carried away!

APCSP - Bits are like Legos

Early Release Schedule

1st period – 8:40-9:35
2nd Period – 9:40-10:35
4th Period – 10:40-11:35
3rd Block – 11:40-1:35

1st Lunch – 11:35 – 12:00
2nd Lunch – 12:05-12:30
3rd Lunch – 12:34-1:00
4th Lunch 1:10-1:35


                                                        
Kaplan's SAT Question of the day
                                                            
MARKETING



LAP:
Data Do It  - 1.05 LAP - Data do it - Due Friday, Sept 14
1.05 Data Do It - LAP Quiz (20)
http://www.quia.com/quiz/6178003.html
Loyalty Cards - What do they track?
VS - What do they track?



Class discussion - Last time you went shopping, what types of data did the store collect on you.

Project:

Mini Project using Movoto
Understanding Data
Data Collection
Secondary Data
Usage for data in making sound business decisions
What data is monitored for marketing decision making?


Problem Solving:
How much income does it take to live there?
Did you find two data points that seemed to show positive correlation with one another?
  You should have found multiple ones.
       If you need a hint:  Check education level and _________, and tell me what it means
        Unemployed and _____________
         Employed and ______________
          Not in the Labor force and _______________
           Where would you put a mcDonalds?
             Upscale restaurant?
               offer home refinancing opportunities?
                 Have the best schools?
                   Have the most opportunity for meaningful and well paying careers?
                    Rent and ________________
                      Household income and _______________?
    Do you see any more correlations?

Allow time for LAPS and HW

                                                                                                                                                    
AP COMPUTER SCIENCE PRINCIPLES
https://studio.code.org/s/express-2018
-----------------------------

HW - Due Sept 12 4th Block

Blown to Bits (www.bitsbook.com), Chapter 1, pp. 4-13. - Read about the following koans (or truths) of bits related to the Internet:
  • Koan 1: It’s All Just Bits
  • Koan 2: Perfection Is Normal
  • Koan 3: There Is Want in the Midst of Plenty
  • Koan 6: Nothing Goes Away
  • Koan 7: Bits Move Faster Than Thought
  • Pick one of these koans and address the following questions:
    • Argue if you agree that it is a “truth” and if it will always be a “truth.”
    • How does this koan intersect with your life as a student?
--------------------


1.10 HW

Due Friday - email

Additional Reflection and Discussion ● An Internet service provider (ISP) just purchased all the routers in your area. What types of things is this ISP capable of doing? Are you comfortable with this arrangement?
This will be graded as a stand along reflection piece from 1.10 code.org assessment questions

-------------------

Unit 1 Assessment review
I need to unlock, but then you can go through the problems that you answered.

-------------------
1.11 Packets and Making a Reliable Internet

1.11 Packets and Making a Reliable Internet

 

Objectives

Students will be able to:

Explain why protocols are necessary to overcome the underlying unreliability of the Internet.
Justify the need for acknowledgements and packet numbering in TCP.
Develop a protocol for reliable communication on the Internet.

Vocabulary

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

Agenda

  • Getting Started (5-20 mins)
Prompt:
Your friend sent you a message on the Internet, but you never received it. Based on what you already
know about routers and the physical Internet, list what reasons might explain this fact.
  • Optional Unplugged Activity (15 mins)
When we communicate on the Internet, we are not just sending short text messages as we did yesterday.
We also use the Internet to exchange documents, videos, music, and scientific data, and these files can easily
grow to enormous size.
All of this would not be a problem if the Internet were perfectly reliable, but in reality, errors sometimes occur.
Wires can be cut, routers can be overwhelmed with traffic, and interference with electric or radio signals can
cause messages to become corrupted. The response to this problem is to split large messages into smaller
pieces of information called packets.
It turns out that splitting up a message into packets provides many benefits. If a faster route opens up halfway
through transmitting a large file, it is easy to reroute later packets in the transmission through that route.
Splitting up a message into smaller chunks doesn’t solve all the problems of unreliability on the Internet.
Packets can still be dropped or arrive out of order.
Today’s challenge is to develop a protocol to reliably send messages even though the network itself is unreliable.

  • Activity (35 mins)
  • Introduce: new version of Internet Simulator - packets and unreliability.
  • Classroom Activity - Worksheet


The version of the Internet Simulator we will be using today has been structured to simulate the
unreliability of the Internet.
In particular you'll notice a few changes:
You will only be allowed to send packets containing 8 characters of text!

     Anything larger than 8 characters will be cut off...

     However, you may construct multiple packets prior to sending them, by clicking "Add Packet",  and then send them all with one click of the "Send" button.

     Every message has a small chance of being dropped on each “hop” it makes between routers.
So……………….

  • Packets and Making a Reliable Internet

  • Challenge: Develop a protocol for reliably sending a message across an unreliable network
  • An Unreliable Internet Simulator: The current version of the Internet Simulator is modeled
  • after some actual constraints of the Internet - Messages must be divided into packets which may contain
  • at most eight (8) ASCII characters - Messages should be long enough to require at least 10 packets -
  • Packets may not arrive in the order sent - Packets may be dropped while in transmission
  • Directions: In a group or individually join a router in the Internet Simulator and practice sending
  • messages given these new constraints. Once you are comfortable with the challenge, iteratively design
  • a protocol that can reliably send a message to a partner. You and your partner should join DIFFERENT routers.
  • Protocol Requirements: - All communication can only be done through the Internet Simulator -
  • You must send a message that spans at least 10 packets (i.e. an 80 character ASCII message). -
  • The protocol should account for the possibility that the characters might be entirely random (i.e. not
  • necessarily English - do not count on human intuition to reconstruct the message. The message is not
  • known beforehand.) - The sender and receiver must be confident the full message was successfully
  • transmitted and reconstructed.


    • Generate Traffic
    Students should recognize:
    • Packets are dropped with some frequency
    • Packets of more than 8 characters are always truncated to just the first 8 characters
    • Packets sometimes arrive out of order.


    • Develop a Protocol
    • All communication can only be done through the Internet Simulator.
    • The full message sent will be at least 80 characters long - broken into at least 10 packets - and might be
    • entirely random (i.e. there’s no way to use human intuition to reconstruct the message).
      • The message is not known beforehand.
    • The sender and receiver must be confident the full message was successfully transmitted and reconstructed.

    • Test Protocols
    • Provide students an opportunity to either present their protocols in written or visual form, or test them out by
    • sending a randomly generated message of your choosing.
    • The goal of this share-out would be to identify the main components of the protocols that groups developed in
    • common.

    • Wrap-up (10 mins)
    • Video: The Internet: Packets, Routing, and Reliability

    • Connect activity to TCP
    • The challenges we encountered in today’s activity very closely mirror those that exist on the actual Internet.
    • The response was the development of a protocol called the Transmission Control Protocol, or more simply, TCP.
    • TCP divides larger messages into smaller packets which have ordering information added to their header.
    • When a packet arrives at a destination computer, an acknowledgement is sent to the sender, letting them
    • know they don’t need to resend that packet.
    • Once all the packets have arrived, the ordering information in the headers of the packets allows them to be
    • reordered to create the original message.

    • Assessment
    • Code Studio: Assessment questions are available on the Code Studio.
    • Extended Learning
    • There and Back Again: A Packet’s Journey and discuss questions that arise about how a packet
    • travels from one person to another. (3:21)
    • Easy Way to Understand Packets. Note: Headphones are recommended; this one has some dramatic
    • music! (13:00)
    • Look at IETF Requests for Comment (RFCs): Protocols are developed by the Internet Engineering
    • Task Force (among other groups), who publish Requests for Comment (or RFCs) detailing the
    • components of the protocol. If students wish, they may have a look at the one of the actual RFCs for
    • TCP here https://www.rfc-editor.org/rfc/rfc793.txt. RFCs exist for many of the protocols covered in
    • this course.
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