The Design of a Flexible Communications Framework for Next-Generation Middleware

The success of middleware platforms is leading to a number of challenges as the motivation grows to deploy middleware in ever more demanding application domains. This paper therefore introduces a flexible, object-oriented communications framework, called BOSSA NOVA, which can be integrated into middleware platforms to better support domains such as soft real-time, multimedia, and adaptive mobile systems. In particular, BOSSA NOVA aims at providing flexibility in terms of protocol structure and composition, protocol granularity, and concurrency/multiplexing structure. The use of reflective interfaces explicitly facilitates management and dynamic reconfiguration as well as QoS specification and negotiation together with associated resource management in protocol graphs. QoS-negotiation protocols and resource-management policies, however, in common with most areas of the framework, are open and non-prescribed, although basic protocols and reusable base functionality are readily provided. For ease of use, BOSSA NOVA relies on only a small set of simple and consistently used abstractions, which allow for efficient implementations.