3.4 Protocols and standards

You have already met the idea of protocols in Section 1 – rules to govern how information is sent, transmitted and received. Protocols can be explained using an analogy with the way people talk to each other. When we talk we don't simply string words together in a random fashion: we have a set of rules (grammar) that determines the order of words and the way sentences are constructed. Understand didn't have other us difficult if it would be quite rules each these for to we. We hope the previous string of words illustrates what we mean! It's a jumbled-up version of the sentence 'If we didn't have these rules it would be quite difficult for us to understand each other.'

We also need to have a shared understanding of what a word means (for example, the word 'trunk' may have quite different meanings in North America and Britain). But we have thousands of versions of these rules – different languages and dialects – so simply having a set of rules isn't enough to ensure good communication. We have to agree to use the same rules (or at least nearly the same rules) or have some mechanism to translate from one set of rules to another.

Fortunately a number of organisations have taken responsibility for ensuring that particular communication protocols are clearly stated, recorded and made available to others. These organisations agree on and produce the necessary standards, which are a kind of technical specification that sets out the rules and requirements to ensure interoperability. A standards document is drawn up with the involvement and agreement of all interested parties, for example representatives of users, manufacturers and government agencies. The dominant standard in wired LANs is one that is commonly known as Ethernet.