Communications Protocol - Protocol Design

Protocol Design

Communicating systems operate in parallel. The programming tools and techniques for dealing with parallel processes are collectively called concurrent programming. Concurrent programming only deals with the synchronization of communication. The syntax and semantics of the communication governed by a low-level protocol usually have modest complexity, so they can be coded with relative ease. High-level protocols with relatively large complexity could however merit the implementation of language interpreters. An example of the latter case is the HTML language.
Concurrent programming has traditionally been a topic in operating systems theory texts. Formal verification seems indispensable, because concurrent programs are notorious for the hidden and sophisticated bugs they contain. A mathematical approach to the study of concurrency and communication is referred to as Communicating Sequential Processes (CSP). Concurrency can also be modelled using finite state machines like Mealy and Moore machines. Mealy and Moore machines are in use as design tools in digital electronics systems, which we encounter in the form of hardware used in telecommunications or electronic devices in general.

This kind of design can be a bit of a challenge to say the least, so it is important to keep things simple. For the Internet protocols, in particular and in retrospect, this meant a basis for protocol design was needed to allow decomposition of protocols into much simpler, cooperating protocols.