AP networking
Paper Messages
AP Career Kickstart Cyber: Networking
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
1
QUESTION:
How do computers represent information?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
2
Your Task
Communicate your answer to your partner using only your piece of origami paper.
No talking or gestures allowed!
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
3
What is your favorite genre of music?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
4
Do you have any pets at home?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
5
Do you play a sport?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
6
Would you live in a treehouse?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
7
What’s better: cake or ice cream?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
8
Is it currently day or evening?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
9
What came first: chicken or egg?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
10
This is great and all, but…
How do I answer a question that has more than two options for answers?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
11
What is your preferred morning beverage?
Coffee, juice, tea, or something else?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
12
Communication Protocol
An agreed upon set of rules
used to transmit information.
How meaning is assigned… arbitrary.
That it is followed… critical.
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
13
Question
How many answers could I represent if I had three (3) pieces of paper instead of two (2)?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
14
For 3 Pieces of Paper 8 OPTIONS!
1
2
3
4
5
6
7
8
Each piece of paper represents a bit (0 or 1, on or off)
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
15
For 4 Pieces of Paper 16 OPTIONS!
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
16
Consolidate
Question 1
Why are protocols important in communication?
Question 2
Why is the origami paper a good physical model for a bit?
Question 3
How many options (or states) can be represented with 10 pieces of paper (or bits)?
Question 4
If I needed to represent 24 different options (or states), how many pieces of paper (or bits) would I need?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
17
AP-2.1.C-OSI Model & Encapsulation
OSI Model & Encapsulation
Guiding Question: How does the OSI Model help standardize network communication, and why is it important for troubleshooting and network design?
Students will:
Understand the purpose of the OSI (Open Systems Interconnect) model
Identify the 7 layers of the OSI (Open Systems Interconnect) model and the layer PDUs
Understand how the OSI layers are used in packet encapsulation
2
OSI Reference Model
What if you bought a wireless router but when you brought it home it would only connect with your laptop but not your dad’s workstation?
What if you sent an email to your friend in Italy, but it got bounced back because it was addressed incorrectly for the Italian section of the Internet?
What if you sent an alert about a tornado threat to all your employees but had no way of knowing who did not get the alert?
These things DON’T happen in today’s networks, and we can thank the OSI Reference Model for that!
OSI Reference Model
Created in 1980s so that there would be a common standard for networking.
BIG advantages!
compatibility of hardware
method to confirm reliability
troubleshooting is simplified
modularity facilitates change
** Notice that the layers are numbered from bottom to top
OSI Layers
Each OSI Model section works as a layer that helps the one above it and is helped by the one below it in delivering digital messages.
Each layer takes a job in the encapsulation process of
digital delivery.
Data Encapsulation Is Like A Bakery
Characteristics of the OSI Layers
As the data moves through encapsulation, it changes form - this is called the Protocol Data Unit
For each Layer we need to know:
Number -- Name -- PDU -- Function performed
Layer 7 Application
PDU – Data
Defines what type of communication is taking place. Email, Web Browsing, Video Streaming, etc.
If a person can see it or interact with it, then it is happening at the application layer.
7
Characteristics of the OSI Layers
Layer 6 Presentation
PDU – Data
Handles conversion from human language to computer languages; also handles encryption.
Data converted isn’t just text - it include file types for pictures, video, audio, etc.
Layer 5 Session
PDU – Data
In charge of starting, maintaining and ending connections between apps.
Can restart an interrupted session.
Characteristics of the OSI Layers
Layer 4 Presentation
PDU – Segments
Determines how the delivery is going to be handled
= chooses between RELIABLE and UNRELIABLE delivery?
Do you want error messages if something goes wrong?
Layer 3 Network
PDU – Packets
Determines what route the packet will take.
IP addressing
Need Layer 3 information to send packet out of
the LAN and onto a WAN.
Characteristics of the OSI Layers
Layer 2 Data Link
PDU – Frames
Establishes communication on the LAN.
MAC addressing.
Messaging about errors at Layer 1.
Layer 1 Physical
PDU – Bits
Defines the specifications of the media used between the sender and receiver.
Ethernet? Wireless? Fiber? What speed?
Internet Abstraction Layers
Internet Abstraction Layers
The TCP/IP model (below) depicts 4-layers of protocols and software.
TCP/IP Model
Abstraction and the Internet
The Internet is organized into abstraction layers.
Simplified Design: Layers interact only with the layers above and below.
Users interact with the Application layer.
Each layer is governed by its own set of protocols.
Application Layer
Transport Layer
Internet Layer
Link Layer
Email: Simple Mail Transfer Protocol (SMTP) Web: HyperText Transfer Protocol (HTTP)
Transmission Control Protocol (TCP): Reliable transmission. Used by email and web apps to order packets, check for transmission errors.
Internet Protocol (IP): Unreliable transmission. Routes packets by IP address across network boundaries to achieve internetworking.
Physical links between computers: Ethernet Protocol, Wifi protocol
Data Flows Through the Layers
Transmit data from source computer (A) to destination (B).
A
B
Data Flows Through the Layers
Transmit data from source computer (A) to destination (B).
Within the source computer, data flows from the Application layer down through the Transport and Internet layers.
A
B
User A requests a Web page from Server B
Data Flows Through the Layers
Transmit data from source computer (A) to destination (B).
Within the source computer, data flows from the Application layer down through the Transport and Internet layers.
Bits move across LAN to the router.
The Internet layer routes the data from network to network.
A
B
The Link and Physical layers move the bits from computer to computer on LAN.
Transmit data from source computer (A) to destination (B).
Within the source computer, data flows from the Application layer down through the Transport and Internet layers.
Bits move across LAN to the router.
The Internet layer routes the data from network to network.
A
B
The Transport and Internet layers work together to send data through the Internet
Data Flows Through the Layers
A
B
Server B receives
request and processes the request.
Transmit data from source computer (A) to destination (B).
Within the source computer, data flows from the Application layer down through the Transport and Internet layers.
Bits move across LAN to the router.
The Internet layer routes the data from network to network.
Within the destination computer, data flows up to the Application layer.
Data Flows Through the Layers
Data Encapsulation
Data are encapsulated into packets at each protocol level.
Analogy: Application data is a “letter”. It is first put into a TCP “envelope”. That is then put into a “IP” envelope. And finally into the “Ethernet” envelope.
Feature
OSI Model
TCP/IP Model
Number of Layers
7
4
Functionality
Theoretical and detailed; breaks down network communication into specific, individual layers for each function.
Practical and streamlined; combines some functions into fewer layers.
Layer Breakdown
Application, Presentation, Session, Transport, Network, Data Link, and Physical.
Application (combines OSI's top three), Transport, Internet, and Network Access (combines OSI's bottom two).
Protocol Dependence
Does not define specific protocols; acts as a reference model.
Based on the specific protocols that make up the internet.
Primary Use
Educational and troubleshooting tool for understanding network processes.
The model used in practice for internet and network communication.
The main difference is that the OSI model is a conceptual framework with seven layers, while the TCP/IP model is a more practical, four-layer model used for internet communication. The OSI model provides a detailed, theoretical breakdown of network functions, whereas TCP/IP combines some of these functions into fewer layers, making it simpler and more widely implemented in real-world applications.
What is the difference?
20
Binary Number Cards
AP Networking
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
1
Times have changed…
8-bit
64-bit
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
2
What is a “bit” anyway?
Did you know it’s actually two words smooshed together?
QUESTION
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
3
Binary Digit
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
4
What does it mean to be
binary (base-2) anyway?
Let’s start by exploring our most familiar base… base-10 (a.k.a. decimal)
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
5
Materials Setup
The ones (1’s) place
The tens (10’s) place
The hundreds (100s) place
Each page will represent a place value in our base-10 number.
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
6
#2
Materials Setup
The ones (1’s) place
The tens (10’s) place
The hundreds (100s) place
Number cards will go into their respective place values.
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
7
How do you make this number?
473
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
8
#2
How do you make this number?
473
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
9
How do you make this number?
324
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
10
#2
How do you make this number?
324
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
11
How do you make this number?
501
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
12
#2
How do you make this number?
501
What is unique about this number?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
13
Let’s switch to a different base for comparison!
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
14
Don’t worry. We got this!
Base-5 Anyone?!
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
15
Using different bases is like
using different languages
English: cat
Spanish: gato
Same concept/object/quantity but expressed
with different words/letters/symbols
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
16
Base-10 pack vs. Base-5 pack
How do the card values differ?
What might this mean for the place values in base 5?
Note that the number of cards in each pack differs!
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
17
What is 37 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
18
#2
What is 37 (decimal) in base-5?
So far, we have 25. We still need more.
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
19
#3
What is 37 (decimal) in base-5?
Now we have 30; we still need more!
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
20
Now we have 35; we still need more!
#4
What is 37 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
21
#6
What is 37 (decimal) in base-5?
We have 37! Now what’s the “number” in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
22
#7
What is 37 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
23
For Comparison
Base-10 (37)
Base-5 (122)
We represent the same quantity (# blue circles) in two different “languages”
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
24
What is 58 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
25
#2
What is 58 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
26
What is 84 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
27
#2
What is 84 (decimal) in base-5?
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
28
Convert each of the following decimal numbers into base-5.
61
19
27
94
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
29
#2
Convert each of the following decimal numbers into base-5.
61
221
19
34
27
102
94
334
©College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
30
Now, we finally get to do BINARY!
(a.k.a. base-2)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
What is in a packet of base- cards?
x9
x9
x9
Packet of “Base-10” cards
x
x
x
Packet of “Base-2” cards
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
Base-10 cards compared to Base-2 cards.
x9
x9
x9
Packet of “Base-10” cards
x1
x1
x1
Packet of “Base-2” cards
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
A full set of base-2 cards
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
How can you make the number 6?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#2
How can you make the number 6?
0
0
0
1
1
0
6 in decimal can be represented as 110 in binary
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
How can you make the number 26?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#3
How can you make the number 26?
26 in decimal can be represented as 11010 in binary
0
1
1
0
1
0
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
How can you make the number 51?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#4
How can you make the number 51?
51 in decimal can be represented as 110011 in binary
1
1
0
0
1
1
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
What if you want to do this
without your number cards?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#1
What if you want to do this
without your number cards?
What is 37 in binary?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#2
What if you want to do this
without your number cards?
What is 37 in binary?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
1
0
1
1
0
0
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#3
What if you want to do this
without your number cards?
What is 22 in binary?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
#4
What if you want to do this
without your number cards?
What is 22 in binary?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
0
1
1
0
0
1
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
What is 110110 (binary) in decimal?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
#1
What is 110110 (binary) in decimal?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
1
1
1
0
0
1
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
What is 110110 (binary) in decimal?
1
2
4
8
16
32
(20)
(21)
(22)
(23)
(24)
(25)
1
1
1
0
1
0
32 + 16 + 4 + 2 = 54
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
Reflection
We did a lot over the last two days! You are not expected to have mastered everything right now. We are still learning and will keep practicing.
Rate your current comfort with the statements below: Scale of 1 to 5, with 1 = totally lost and 5 = I can teach it!
If given a base, I know what the place values for that base will be. (e.g. base-2, values: 1, 2, 4, 8, …)
If given a base between 2 and 10, I can tell you what the digits are used in that base (e.g. base-5 uses 0, 1, 2, 3, and 4)
I can convert from base-10 to another base.
I can convert from another base to base-10.
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
2.1 Segments, Packets, and Frames, Oh My!
Encapsulation & De-Encapsulation
AP CK Cyber: Networking
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
When you order something from an online store, how does it get from the warehouse to you?
Shopping image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Consider the following made-up address:
123 Network Road
Switchville, NY 09876
What part of the address matters at each stage of delivery?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Consider the following made-up city for this address:
123 Network Road
Switchville, NY 09876
Use city / state to get to the next distribution center
What part of the address matters at each stage of delivery?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Consider the following made-up zip code for this address:
123 Network Road
Switchville, NY 09876
Use zip code to get to the local post office
What part of the address matters at each stage of delivery?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Consider the following made-up street address:
123 Network Road
Switchville, NY 09876
Use street name and number to get to correct place
What part of the address matters at each stage of delivery?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
NOW…Consider the following made-up address:
123 Network Road
Switchville, NY 09876
Use street name and number to get to correct place
What part of the address matters at each stage of delivery?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
The encapsulation/de-encapsulation process
CK Pilot Course Guide p. 59
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Sit together and decide on a name for your group!
Create a group that includes the entire OSI Model.
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Now meet with the others that have your same layer(s) to discuss what happens in your layer and its importance!
Solo Flight:
What do you remember about the OSI model?
Respond to the questions about your layer on the handout.
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Who Gets What?
Layers 5-7
Index card
Layer 4
Post-it & smallest bag
Layer 3
Post-it & medium bag
Layers 1-2
Post-it &
biggest bag
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
As we go…
Use your handout to capture new vocabulary.
Any time you hear new networking term, write it down!
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Hey, Layers 5-7!
What are the names of your layers again?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Here’s your job:
Generate a piece of data on your index card (quote, picture, fun fact, riddle, etc.)
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
The original data needing to be sent from one computer to another originates in the upper layers of the OSI model, or the application model of the TCP/IP model.
At these layers, the data is formatted and potentially encrypted in its preparation to go to the next layer. At these layers the PDU (or protocol data unit) is called data.
Layers 5, 6, & 7
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Hey, Layer 4!
What is your layer
name again?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
If you chose UDP use another sticky note and write datagram.
If you chose TCP, write segment.
On a post-it write either
UDP or TCP and some number
between 1 and 65,535.
Here’s your job Layer 4:
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
TCP (transmission control protocol) and UDP (user datagram protocol) are both protocols that are associated at the transport layer. They determine whether data gets sent in a way where it is acknowledged when received or if it just gets sent without acknowledgement.
Typically, at this layer, a port number is assigned. Different protocols default to different logical ports (as opposed to a physical port like a USB-C port). These work like a mailbox number once it reaches its destination. The port number determines which application gets it! One of the most common ones are ports 80 and 443 for web pages (HTTP and HTTPS).
Layer 4
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Layer 4
Take your data and put it inside your bag and add the sticky notes to the outside.
Depending on whether TCP or UDP is used to send the data, the protocol data unit or PDU is called either a segment (TCP) or a datagram (UDP). Layer 4 just encapsulated the data. In other words, it wrapped it with other important information that is used for delivery to the proper host.
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Hey, Layer 3!
What is the name of your layer again?
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Use a sticky note to fill out the following information:
TO: <<Destination team name>>
FROM: <<Your team name>>
Here’s Your Job, Layer 3:
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Image comes from Bitmoji – feel free to make your own / adjust the graphic to suit your interests (or your students’ interests)
Here’s Your 2nd Job, Layer 3:
On a separate sticky write:
packet
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
In real-life, the packet created at this step will typically use an IP address instead of a “team name”. This information will determine whether this piece of data needs to go outside of your network. If outside your network, it will go through different routers to eventually get to the intended network (or in our case, the appropriate team). The key here is that Layer 3 is responsible for the addressing that gets the data between different networks.
Layer 3
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
What are the names of your layers again?
Hey, Layers 1-2!
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Here’s Your Job , Layers 1 & 2:
Use a sticky note to write
TO: <<Destination student name>>
FROM: <<Your team’s student name>>
It’ll be the Layers 5-7
team members!
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Here’s Your Job, Layer 2:
On a separate sticky write:
frame
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
In real-life, the frame that is created at this step will typically use a MAC address instead of a student’s name. Once the frame gets to the right network, the information that was added at this layer will tell the network which computer or host within it should receive the message. The key here is that Layer 2 is responsible for the addressing that gets the data to the right host within a network.
Layer 2
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Take your packaged data to the appropriate team!
(Layer 1-2 team member!)
Here’s Your Job , Layer 2: :
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
Layer 1’s job is to send the frame’s data as bits through whatever medium is used. This might be electricity through a copper wire, light through a fiber optic wire, or radio waves through the air. Either way, all that information that they had – the data, UDP/TCP information, and the different addresses – gets sent through the transmission medium to be received by the next host.
Layer 1
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
De-encapsulate It!
Layers 1-2, remove the frame info.
Layer 3, remove the packet info.
Layer 4, remove the segment or datagram info.
Layers 5-7, read the data!
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
On the receiving host, the data gets unpacked at every layer. The frame is unpacked to become a packet, the packet becomes a datagram/segment, and then the original data is recovered. It is important to note that at each unpacking stage, the data’s integrity is checked to make sure nothing was corrupted along the way.
Let’s…De-encapsulate It!
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.
The encapsulation/de-encapsulation process
CK Pilot Course Guide p. 59
© College Board These materials are part of a College Board pilot program. Use or distribution of these materials online or in print beyond your school’s participation in the pilot program is prohibited.