A flexible middleware for multimedia communication: Design, implementation, and experience

Distributed multimedia applications require a variety of communication serv ices. These services and different application requirements have to be prov ided and supported within: 1) end-systems in an efficient and integrated ma nner, combining the precise specification of quality-of-service (QoS) requi rements, application interfaces, multicast support, and security features a nd 2) the network. The Da CaPo++ system presented in this paper provides an efficient end-system middle-ware for multimedia applications, capable of h andling various types of applications in a modular fashion. Application nee ds and communication demands are specified by values in terms of QoS attrib utes and functional properties, such as encryption requirements or multicas t support, Da CaPo++ automatically configures suitable communication protoc ols, provides for an efficient runtime support, and offers an easy-to-use, object-oriented application programming interface. While its applicability to real-life applications was shown by prototype implementations, performan ce evaluations have been carried out yielding practical experiences and num erical results.