In telecommunications, a protocol is a system of rules that allow two or more entities of a communications system to transmit information. The medium can be any kind of entity.
What is PROTOCOL
- Important aspects of networks that are neither devices nor media are rules or protocols. These rules are the standards and protocols that specify how the messages are sent, how they are directed through the network, and how they are interpreted at the destination devices.
- For example, in the case of Jabber instant messaging, the XMPP, TCP, and IP protocols are all important sets of rules that enable our communication to occur.
- These are the rules or standard that defines the syntax, semantics, and synchronization of communication and possible error recovery methods. Protocols may be implemented by hardware, software, or a combination of both.
They use well-defined formats (protocol) for exchanging messages.
- Each message has an exact meaning intended to elicit a response from a range of possible responses pre-determined for that particular situation.
- The specified behavior is typically independent of how it is to be implemented. Communications protocols have to be agreed upon by the parties involved.
- To reach an agreement, a protocol may be developed into a technical standard. A programming language describes the same for computations, so there is a close analogy between protocols and programming languages: protocols are to communications as programming languages are to computations.
Most commonly used devices in a networking
- Switch - the most common device for interconnecting local area networks
- Firewall - provides security to networks
- Router - helps direct messages as they travel across a network
- Wireless Router - a specific type of router often found in home networks
- Cloud - used to summarise a group of network devices, the details of which may be unimportant to the discussion at hand
- Serial Link - one form of WAN interconnection, represented by the lightning bolt-shaped line