A timed-SDL for performance modeling of communication protocols

In this paper, we use SDL (Specification and Description Language, CCITT Z.100) to express the abstract functional designs of communication protocols. To make performance predictions possible for these abstract functional designs, a timed-SDL is developed to incorporate timing and probabilistic specifications into the original SDL functional descriptions. By introducing the timed-SDL, extra implementation-dependent information can be added into the abstract functional designs to form their performance models. Both functional simulation and timing simulation of communication protocols can be performed directly on these performance models. A simple example of ATM modeling is given for illustration