Depending upon a person’s background the word ‘protocol’ will conjure up different considerations. Historically it refers to, and still does in the right context, social and diplomatic behaviour:
‘The official procedure or system of rules governing affairs of state or diplomatic occasions.’ (English Oxford Dictionaries)
‘The accepted or established code of procedure or behaviour in any group, organisation, or situation.’ (English Oxford Dictionaries)
Then there is the modern, technologically based, understanding:
‘A set of rules governing the exchange or transmission of data between devices.’ (English Oxford Dictionaries)
‘A computer language allowing computers that are connected to each other to communicate.’ (Cambridge Dictionary). N.B. Computers do not have to be physically connected.
It is the latter this discussion is primarily concerned with. Nevertheless, in whichever context the term is used, it refers to rules, procedures and systems of behaviour.
The word originates from the Greek ‘protocollons’ meaning: Leaf of paper glued to a manuscript volume that describes content.
Why this discussion?
Protocols are very much a technical matter and would not usually be a relevant topic of discussion for a website such as this. However, when researching and discussing various other topics, protocols frequently arise as being an integral part e.g. URL (Uniform Resource Locator); IP Addresses. It therefore makes sense to have some understanding of them. This is only intended to be an overview within which technical points are only mentioned where they help with general understanding.
Whether a user realises it or not, protocols are in constant use in information technology e.g. e-mails; internet; websites; blogs; social media; downloads; etc. Protocols are basically special sets of rules that the two ends of a telecommunication require and use to talk to each other. (Computer; internet; etc. communications are telecommunications.) They comprise formal standards and policies for such communications and govern end-to-end processes enabling timely, secure and managed sharing.
In a human conversation people usually need to use the same dialect though, generally, they do not have to abide by strict rules of grammar or language. However, computers require everything to be defined and structured. They need to know how and in what format information is to be exchanged. Protocols establish and provide these standard formats.
Protocols are established by international agreement. This ensures devices, no matter where in the world they are located, are able to ‘talk’ to each other.
Protocols are the equivalent of computer programming language but are specifically designed for communicating.
Many different protocols exist. Each is designed for a specific function and several are used within each communication. The information is broken down into small portions each of which is then transmitted by the appropriate, individual, protocol. In effect several protocols are ‘stacked’ and form a ‘set’ that the systems then utilise. This, breaking down and multiple protocol use, assists speedy communication as different segments are able to be sent by different routes. These are then reassembled, in the correct order, as defined by the protocols, at the end destination.
As indicated above, this is not intended to be an in-depth review of protocols. Nevertheless, it may help to have a little understanding regarding the sort of information they define and communicate. The following is by no means exhaustive; just a few elements are mentioned in hope it will assist with the reader’s general comprehension. Among other things they will define:
- Date format.
- Address format (sender and receiver): Enables systems to identify whether the communication is intended for it or should be ignored.
- Address mapping: Defines which communication system to be used e.g. Wi-Fi, Ethernet.
- Routing: Where systems are not directly connected the appropriate route for communicating has to be found.
- Detection of errors.
- Acknowledgment of receipt.
- Loss of information: Timeouts etc.
- Direction of flow: When communication can only occur in one direction.
- Sequence control: Controls the order in which the segments, portions, of information (referred to above) are to be sent.
- Flow control: Needed where the communication is transmitted at a faster rate than the receiving device can process.
As mentioned at the start, the subject of protocols is very much a technical and complicated matter. However, as they play an important, daily, part of modern life it helps to have some understanding of what they do.