networks

课 Progress

0% Complete

Networks

What is a network?

Networks are a set of interconnected devices (such as computers, printers, and servers) designed to:
- share resources
- exchange data
- communicate with each other
The main purposes of a network is to enable data and resource sharing, communication, and collaboration

Purpose & importance of protocols

Network protocols define the rules and formats that devices must follow to communicate with each other over the network
They ensure successful and secure data transmission, and help maintain order and efficiency in communications
Examples of protocols include HTTP, FTP, TCP/IP, and SMTP, among others

Understanding the term “standard”

A standard in a network or any data transfer situation refers to a set of guidelines or frameworks that govern how a task should be performed or how a product should function
Standards ensure compatibility, interoperability, and consistency across different devices and software

Purpose & need for standards in a network

Standards enable different network devices, regardless of their manufacturer or model, to work together seamlessly
They ensure that data can be correctly interpreted and processed by the receiving device, regardless of where or how it was sent
Standards support network expansion and the integration of new technologies without disrupting existing operations
They foster innovation and competition by providing a common ground for all manufacturers and developers

Common internet protocols

Protocol	Notes
HTTP (HyperText Transfer Protocol)	Primary protocol for transferring web content (text, images, video) Works as a request-response protocol in a client-server computing model
HTTPS (HTTP Secure)	A version of HTTP, but with encryption for security Used for secure transactions like online banking and shopping
SMTP (Simple Mail Transfer Protocol)	The standard for sending email messages between servers It is also used to send emails from a client to a server for further forwarding
FTP (File Transfer Protocol)	Used for transferring files from one host to another over a network Provides authentication (username and password) and can manage file directories
ARP (Address Resolution Protocol)	Translates IP addresses into MAC (Media Access Control) addresses This ensures that data packets reach the correct device on a network
TCP (Transmission Control Protocol)	Part of the main suite of protocols used in the Internet Protocol Suite Provides reliable, ordered, and error-checked delivery of a stream of packets
UDP (User Datagram Protocol)	A simpler message-based connectionless protocol UDP does not guarantee delivery by disregarding order and error-checking, making it faster
IP (Internet Protocol)	Functions mainly by addressing and routing packets of data from the source to the target device

Worked Example

The internet can be considered an example of a WAN.
The internet uses a set of protocols referred to as the TCP/IP stack. The TCP/IP stack consists of four different layers, each with its own set of protocols.

Explain why protocols are important on a network

2 marks

How to answer this question:

You need to know what network protocols are and why they are important for network communication:
- They allow us to communicate over a network by ensuring that all communicating parties use the same rules and standards
- Whatever data or signals are sent need to be understood commonly by both the sender and the receiver

Answer:

Example answer that would get full marks:

Protocols are rules that must be followed to allow communication over a network. They ensure that all devices follow the same rules and standards so that they interpret data and signals in the same way.

Computer-Science-A-level-Ocr