This paper proposes the modeling and the performance analysis of a high-level control protocol – COCOP, which enables cooperative groups of clients to control a shared server delivering time-dependant data services. Several synchronous multimedia systems such as media on-demand, web casting, and networks of real/virtual sensors, can beneficially exploit COCOP to furnish cooperative control sessions. The protocol can be mapped onto a multicast transport support based either on IP-multicast or on an application level multicast infrastructure. An event-driven simulation framework is purposely customized and exploited to analyze the protocol performance and thus the dynamics of a cooperative control session over simple, yet representative topologies.