Section 2.0.0

CSN-1.A:  Explain how computing devices work together in a network.

• • CSN-1.A.1 A computing device is a physical artifact that can run a program. Some examples include computers, tablets, servers, routers, and smart sensors. 

  • CSN-1.A.2 A computing system is a group of computing devices and programs working together for a common purpose. 

  • CSN-1.A.3 A computer network is a group of interconnected computing devices capable of sending or receiving data. 

  • CSN-1.A.4 A computer network is a type of computing system.

  • CSN-1.A.5 A path between two computing devices on a computer network (a sender and a receiver) is a sequence of directly connected computing devices that begins at the sender and ends at the receiver.

  • CSN-1.A.6 Routing is the process  of finding a path from sender to receiver.

  • CSN-1.A.7 The bandwidth of a computer network is the maximum amount of data that can be sent in a fixed amount of time. 

  • CSN-1.A.8 Bandwidth is usually measured in bits per second. 

CSN-1.B: Explain how the internet works

• • CSN-1.B.1 The Internet is a computer network consisting of interconnected networks that use standardized, open (nonproprietary) communication protocols. 

  • CSN-1.B.2 Access to the Internet depends on the ability to connect a computing device to an Internet connected device.

  • CSN-1.B.3 A protocol is an agreed-upon set of rules that specify the behavior of a system.

  • CSN-1.B.4 The protocols used in the Internet are open, which allows users to easily connect additional computing devices to the Internet.

  • CSN-1.B.5 Routing on the Internet is usually dynamic; it is not specified in advance.

  • CSN-1.B.6 The scalability of a system is the capacity for the system to change in size and scale to meet new demands. 

  • CSN-1.B.7 The Internet was designed to be scalable.

CSN-1.C: Explain how data are sent through the Internet via packets

• • CSN-1.C.1 Information is passed through the Internet as a data stream. Data streams contain chunks of data, which are encapsulated in packets.

  • CSN-1.C.2 Packets contain a chunk of data and metadata used for routing the packet between the origin and the destination on the Internet, as well as for data reassembly

  • CSN-1.C.3 Packets may arrive at the destination in order, out of order, or not at all.

  • CSN-1.C.4 IP, TCP, and UDP are common protocols used on the Internet.

CSN-1.D: Describe the differences between the Internet and the World Wide Web

• • CSN-1.D.1 The World Wide Web is a system of linked pages, programs, and files.

  • CSN-1.D.2 HTTP is a protocol used by the World Wide Web.

  • CSN-1.D.3 The World Wide Web uses the Internet.

CSN-1.E: For fault-tolerant systems like the internet, 

1. Describe the benefits of fault tolerance.

2. Explain how a given system is fault tolerant.

3. Identify vulnerabilities to failure in a system.

• CSN-1.E.1 The Internet has been engineered to be fault tolerant, with abstractions for routing and transmitting data. 

• CSN-1.E.2 Redundancy is the inclusion of extra components that can be used to mitigate failure of a system if other components fail.

• CSN-1.E.3 One way to accomplish network redundancy is by having more than one path between any two connected devices.

• CSN-1.E.4 If a particular device or connection on the Internet fails, subsequent data will be sent via a different route, if possible.

• CSN-1.E.5 When a system can support failures and still continue to function, it is called fault-tolerant. This is important because elements of complex systems fail at unexpected times, often in groups, and fault tolerance allows users to continue to use the network.

• CSN-1.E.6 Redundancy within a system often requires additional resources but can provide the benefit of fault tolerance.

• CSN-1.E.7 The redundancy of routing options between two points increases the reliability of the Internet and helps it scale to more devices and more people.