Abstract. Contextual collaboration seamlessly integrates existing groupware technologies into a uniform user experience that combines synchronous and asynchronous interactions. This user experience is usually supported by a contextual collaboration infrastructure that needs to efficiently cope with the fast switching and integration of different modes of interaction. This paper experiments with a new model for contextual collaboration based on the notion of generic shared objects. We describe a native implementation of this model and evaluate its behavior under different media traffic conditions. We compare the native implementation with an alternative implementation that integrates existing notification and meeting servers to deliver the same model behavior. We discuss trade-offs and limitations of those two implementations.