IT - Learning Aim B - Features and processes of data transmission

Protocols 

A protocol is a set of rules defining common methods of data communication. These rules need to be standard across all devices in order for them to communicate with each other. A protocol can specify many different things, the format of the data packets, the addressing system, transmission speed, error checking procedures being used.  

Email protocol 

A mail server acts as a virtual post office for all incoming and outgoing mail. The server routes mail according to its database of local network user email addresses as it comes and goes and stores it until it can be retrieved. 

Post Office Protocol (POP3) - is responsible for retrieving emails from a mail server that temporarily stores your incoming mail. When emails are retrieved they are transferred to your local computer, tablet or phone, and deleted from thE server. As a result, if you are using different devices to access email via POP3, you will find that they don't sync the same emails on each device.  

Instant message Access Protocol (IMAP) This is a protocol designed to keep emails on the server, thus maintaining synchronicity between devices

Simple Mail Transfer Protocol (SMTP) is used to transfer outgoing mail from one server to another or from an email client to the server when sending an email. 

Video and video calls over the internet 

Voice of Internet Protocol (VoIP) allows users to make free, or very low cost, telephone calls over the internet. In a business using VoIp, and employee can call any telephone in the world and anyone can call the VoIP telephone regardless of what equipment or network the person uses. 

Because VoIP uses digital internet technologies, many features and services that are very expensive using traditional telephone technology are available free. These include; Voicemails sent to your email, call diverts and call conferencing. 

Web page protocols 

HTTP (HyperText Transfer Protocol) is the standard protocol for browsers to render web pages. It defines how messages are formatted and transmitted, and what action web servers and browsers should take in response to various commands. When you enter a URL in your browser, this sends an HTTP command to the web server directing it to fetch and transmit the requested web page. 

TCP/ IP (Transmission Control Protocol / Internet Protocol) is a suite of transmission protocols used worldwide to connect internet devices on the internet. 

TCP defines how applications can create channels of communication across a network. It specifies how a message is assembled into smaller packers before being transmitted over the internet and reassembled in the right order at the destination. 

IP defines how to address and route each packet to make sure it reaches the right destination. Each gateway computer on the network checks this IP address to determine where to forward the message.

HTTPS (secure protocol) encrypts the information so that it cannot be understood if it is hacked. Banks and many other organisations always use the https…