In order to model telecommunications services as mobile agent system, we are defining a methodology based on the RM-ODP standards. Our approach makes the distinction between the service behavior specification, that is independent of the support environment, and the complete service specification that must take into account the target environment. To obtain this specification, the designer must be able to model the target environment according to the concepts used in the methodology, i.e., the RM-ODP concepts. We describe in this paper such a modeling activity. The target environment that we consider is an OMG-MASIF compliant mobile agent platform. We model it by using the RM-ODP engineering language.