Interaction testing: introducing class of failures by the example of the protocol POP3

This paper examines the problem of the interaction testing for protocol finite state presentation. This method of presentation was used in designing tests in accordance with the specification. Finite state model can be obtained from the protocol description directly in SDL. In the paper the simple post office protocol POP3 is considered as an example, possible interprocessor interferences under different realizations of the protocol are described. The class of failures, which are supposed to reveal in testing interaction is introduced.