It is clearly perceived the exponential growth of on-board electronics on several technological segments. On aerospace segment that is not different. Besides those propulsion and navigation fundamentals systems, necessary on most part of the aircrafts, many complex electronic systems are required: for the treatment of information sent by either landed equipments or other aircrafts (often found on military applications), and for comfort and entertainment systems (most related to passenger transportation applications). In any case, the amount of available and exchangeable information between these systems is fairly huge. Such data exchange would be easier performed if were made through the application of a communication protocol. This paper lists and analyses the communication protocols used by most part of the current and future aircrafts. The intention of this document is to be a study guideline of avionics related protocols.