The major challenge in the design of an efficient distributed multimedia system is the integration and support of a wide variety of applications. Investigating the basic issues involved in the design and specification of distributed multimedia systems is the focus of this paper. A basic layered network architecture is proposed as the uniform framework for the investigation of different levels of functionality typically associated with the communication network that supports multimedia communication. Within this framework, we propose to identify the communication requirements for multimedia applications and characterize a set of communication primitives which specify different qualities of service to reflect different real-time requirements. This investigation is guided by an efficient and flexible multi-level specification model. We will characterize this model and show that the model can be amenable to the construction of a set of communication primitives that support synchronization and communication of multimedia applications.