![Learning Objectives:
1. LO 6.1.1 Explain the abstractions in the
Internet and how the Internet functions.
[P3]
2. LO 6.2.1 Explain characteristics of the
Internet and the systems built on it. [P5]
3. LO 6.2.2 Explain how the characteristics of
the Internet influence the systems built on
it. [P4]](https://image.slidesharecdn.com/lesson4-170217164629/85/Lesson4-9-d-u4l3-hierarchy-of-open-protocols-18-320.jpg)
Lesson4.9 d u4l3 hierarchy of open protocols
- 1. L.O: STUDENTS WILL BE ABLE TO EXPLAIN HOW A HIEARCHY OF OPEN PROTOCOLS MANAGES THE COMPLEXITY OF THE INTERNET. 15-30 minutes (<1 class period) DO NOW: READ Unit 4 Lab 3: Communication Protocols, Page 3
- 2. When you use the internet , a lot of things are going on behind the scenes…
- 3. There are billions of devices connected to the Internet, and hundreds of different kinds of devices: laptops, tablets, phones, refrigerators, handheld credit card readers, and so on. How do they all know how to find and talk to each other? Protocols (standards) ensure that the variety of devices interact with each other smoothly. There are many many many internet protocols! The Internet was designed with several layers of abstraction that sort the protocols according to what part of the process they support.
- 4. Internet Abstraction Hierarchy This hierarchy of abstractions manages the complexity of the Internet by hiding the details of lower levels of the system. The highest level of abstraction includes the most general features of the Internet that have to work the same across all devices. At lowers levels of abstraction, things get more device-specific.
- 5. Application Layer Protocols are the highest level of abstraction because they manage how data is interpreted and displayed to users. These protocols give meanings to the bits sent by the lower protocols. This is abstraction because: this is where the bits and bytes (the ones and zeros of binary) are turned into what you see on the screen HTTP and DNS are examples of application layer protocols... use HTTP (HyperText Transfer Protocol) is used by your internet browsers (Safari, Chrome, Internet Explorer) to interpret HTML instructions for page formatting (HTTP turns the ones and zeros into a webpage)! DNS (Domain Name System) converts the user friendly web addresses into IP addresses. Example you type: Youtube.com….DNS turns what you typed into 128.68.111.01. then the internet looks for that IP address Your email inbox may use SMTP (Simple Mail Transfer Protocol) to send and IMAP (Internet Message Access Protocol) to read email.
- 6. Transport Layer Protocols manage the breakdown of a message into packets to be transmitted by lower level protocols and also the reconstruction of the message from the packets upon arrival. Transport Layer protocol Examples: TCP (Transmission Control Protocol and UDP (User Datagram Protocol)
- 7. TCP versus UDP TCP (Transmission Control Protocol) used for reliable, long-term connection between two computers by only displaying data once all packets have arrived. When you want the sent data to be accurate!
- 8. TCP versus UDPWhen speed is more important than accuracy, people use UDP (User Datagram Protocol), such as for real-time video streaming, where one missed packet doesn't matter much.
- 9. Internet Layer Protocols manage the pathways that the data packets travel across networks. These protocols treat the Internet like one large network even though the physical reality on the lower level is one of many tiny subnetworks. Internet Layer Examples: Every device on the Internet needs an IP address so other devices can find it. IP (Internet Protocol) addresses are upgrading from IPv4 to IPv6. Routers use Internet layer protocols to detect and work around network congestion.
- 10. Network Interface Hardware (Link Layer): All Internet devices connect through a physical interface that uses a protocol to manage the connection to the local network. These local protocols are the least abstract because they deal directly with your physical hardware. Link Layer Examples: this is the layer of Ethernet cables and WiFi radio antenna inside the case. Both connects computers to a local network router which then connects to an Internet provider. Cell phones use a longer-range cellular connection to a phone carrier.
- 11. Open Protocols • Before the internet, there were several different network protocols….back then, a particular brand of computer or router could only talk to the SAME computer brand!!! • Today with open standards: all devices on the internet can “cooperate”. ANY hardware device or software can talk to any other one WITHOUT having to ask permission….
- 12. Open protocols: Your T-Mobile can talk to verizon
- 13. Open protocols: You can send an email from the US to an enemy country
- 14. Open protocols: Your computer with Microsoft can talk to Apple computers.
- 15. Make sure you understand these important Internet protocols: 1. HTTP: HyperText Transfer Protocol—the protocol that your browser uses to access an HTML webpage 2. DNS: Domain Name System—the hierarchical addressing protocol that is human-readable 3. TCP: Transmission Control Protocol—the protocol that assures reliable transmission of data 4. IP: Internet Protocol—the hierarchical addressing protocol that manages routing of data between computers; we are upgrading from IPv4 to IPv6 for more addresses
- 16. Now: Read Blown to Bits pages 309-312.
- 17. Enduring Understandings: • EU 6.1 The Internet is a network of autonomous systems. • EU 6.2 Characteristics of the Internet influence the systems built on it.
- 18. Learning Objectives: 1. LO 6.1.1 Explain the abstractions in the Internet and how the Internet functions. [P3] 2. LO 6.2.1 Explain characteristics of the Internet and the systems built on it. [P5] 3. LO 6.2.2 Explain how the characteristics of the Internet influence the systems built on it. [P4]
- 19. Essential Knowledge: • EK 6.1.1B An end-to-end architectures facilitates connecting new devices and networks on the Internet. • EK 6.1.1C Devices and networks that make up the Internet are connected and communicate using addresses and protocols. • EK 6.1.1D The Internet and the systems built on it facilitate collaboration. • EK 6.1.1E Connecting new devices to the Internet is enabled by assignment of an Internet protocol (IP) address.
- 20. Essential Knowledge: • EK 6.1.1F The Internet is built on evolving standards, including those for addresses and names. • EK 6.1.1H The number of devices that could use an IP address has grown so fast that a new protocol (IPv6) has been established to handle routing of many more devices. • EK 6.1.1I Standards such as hypertext transfer protocol (HTTP), IP, and simple mail transfer protocol (SMTP) are developed and overseen by the Internet Engineering Task Force (IETF). • EK 6.2.1A The Internet and the systems built on it are hierarchical and redundant.
- 21. Essential Knowledge: • EK 6.2.1D Routing on the Internet is fault tolerant and redundant. • EK 6.2.2B The redundancy of routing (i.e., more than one way to route data) between two points on the Internet increases the reliability of the Internet and helps it scale to more devices and more people. • EK 6.2.2D Interfaces and protocols enable widespread use of the Internet. • EK 6.2.2E Open standards fuel the growth of the Internet.
- 22. Essential Knowledge: • EK 6.2.2F The Internet is a packet-switched system through which digital data is sent by breaking the data into blocks of bits called packets, which contain both the data being transmitted and control information for routing the data. • EK 6.2.2G Standards for packets and routing include transmission control protocol/Internet protocol (TCP/IP).
- 23. Essential Knowledge: • EK 6.2.2H Standards for sharing information and communicating between browsers and servers on the Web include HTTP and secure sockets layer/transport layer security (SSL/TLS). • EK 6.3.1M Certificate authorities (CAs) issue digital certificates that validate the ownership of encrypted keys used in secured communication and are based on a trust model.
Editor's Notes
- #2: Page 3: A Hierarchy of Open Protocols. Have a high level understanding of the Internet protocol layers and how they function together: Application, Transport, Internet, and Network Interface. Understand that a protocol is an agreed upon set of communication standards. Page 3: A Hierarchy of Open Protocols. Discussion: Consider having students describe each of the Internet Abstraction Hierarchy layers: Application, Transport, Internet, and Link (hardware). What is the Internet? How is the Internet built? How does the Internet function? (These are essential questions for Big Idea 6: The Internet in the AP CS Frameworks.)
- #4: Page 3: A Hierarchy of Open Protocols. The Internet is a great example of how important abstraction is in permitting such a complicated social artifact to work. Any programmer can write an Internet-based application because that app is supported by the solid framework of the three lower levels. Otherwise the app writer would need expertise in dozens of arcane problems. The student pages mentions briefly that the Internet is also a great example of the importance of cooperation. In a social era that glorifies competition, the Internet is an amazing counterexample. This student page simplfies the Internet Abstraction Hierarchy: The student pages equates the Link Layer with hardware, but that's a simplification. Virtual networks, built entirely out of software, are an example of a non-hardware Link Layer protocol. The student pages don't address any protocols at the Internet layer other than IP itself, but there are several more, including experimental proposed IP replacements that run in parallel with IP over the same physical infrastructure. Similarly, at the Transport layer we emphasize TCP and its reliability role, mentioning UDP in passing and ignoring such esoterica as the Licklider Transmission Protocol (LTP), designed for efficient transmissions to and from computers in outer space. And of course there are many, many specialized Application protocols, some of which are used by routers to learn information about network connectivity, while others are for specific commercial organizations.