The Internet
Internet vs. World Wide Web (WWW)
The Internet is a network of interconnecting networks, which are governed by the Internet Protocol Suite (TCP/IP). The WWW is an application run on the Internet.
How does redundancy support fault tolerance on the Internet
Redundancy provides multiple paths between devices, so if one connection fails, the data can be sent through an alternate route and allow the system to continue functioning.
The difference between parallel and distributed computing
Parallel computing involves the use of multiple processors on a single computer to run a program, while distributed computing involves the use of multiple networked computers to run a program
Open Standards
A standard used on the Internet that makes Internet protocols free to access and use. Open standards allow any device to communicate with any other devices on the Internet.
Benefit of Open Standards on the Internet
Allows for the growth of the Internet
A student is uploading a project to a cloud server. Halfway through the upload, a router on the original path fails. Despite this, the upload completes successfully. What explains this outcome?
The data was rerouted due to redundant paths in the network
Speedup
The “speedup” of a parallel solution is measured in the time it took to complete the task sequentially divided by the time it took to complete the task when done in parallel.
Bandwidth
The rate at which data is downloaded or uploaded in a network. It is a range of frequencies within a given band, used to transmit a signal.
Why is the Internet scalable?
It is designed to handle growth by using shared systems for identifying devices and directing data that support adding more devices and networks
A company uses a network of servers to host its website. One server goes offline during high traffic hours, but users don’t experience any issues accessing the site. What Internet design principle is demonstrated here and why is it important?
Fault tolerance; the system continues to work because traffic was rerouted to other servers. Availability was maintained even during failure.
Scenario: When It is More Useful to Use Sequential Computing than Parallel Computing?
When most of the steps of a program are dependent on results from previous steps.
Latency
The amount of time it takes to send data from sender to receiver (client or server).
Why might a developer choose to compress files before sending them over the Internet?
To reduce the amount of data being sent, which uses less bandwidth and allows the files to load or transfer faster
Devices A and H are part of a network. Three connections on the network fail, but devices A and H are still able to communicate. What computing concept makes this possible?
Redundancy. In a redundant network, more than one path connects devices, allowing them to still communicate when some connections fail.
What is a limitation of parallel computing?
Some problems cannot be easily broken into independent parts, which limits the benefits of using multiple processors.
IP vs TCP vs UDP
IP = Internet Protocol The Transmission Control Protocol (TCP) is used to ensure reliable transport of those packets, with sequencing, acknowledgement, and retries. A faster but less reliable transport protocol is the User Datagram Protocol (UDP).