An analogy to protocols in buses is standards in electrical wiring and telephone circuitry. There are rules about what kind of wire to use, what shape to make the receptacles, how much current and how high a voltage is used, and so forth. In addition to these static or factual rules, there are dynamic rules which govern sequences of actions. In the world of telephones, the completion of a number dialing results in a signal that causes the other party's phone to ring. If they do not answer within a certain time period, the telephone circuitry may cut it off. Also, if the phone is taken off the hook but no number is dialed within a certain amount of time, the telephone company causes a loud buzz or beep to be heard or plays a message about putting the receiver back on the hook.

The bus contention method presented above is a decentralized control protocol. When multiple would-be bus initiators attempt to gain control, they discover that someone else has interfered and then they back off for a while. It is decentralized because no one circuit is given ultimate decision power -- they all share the power in a polite manner. Such decentralized protocols are often used on local area networks, such as Ethernet.