Structured Design of Communication Protocols *

We propose a compositional technique to design multifunction protocols. The technique involves rst designing the protocols performing the various functions separately and then combining them using a set of constraints. The constraints are used to specify the interactions between the component protocols. The interactions, for example, specify when a function has to be performed and whether two functions can be performed concurrently or not. We illustrate the use of our technique by designing several protocols. We give suucient conditions to infer properties of the composite protocol from those of the component protocols.