Multicast Services for Multimedia Collaborative Applications

This work aims at providing multicast services for multimedia collaborative applications over large inter-networks such as the Internet. Multimedia collaborative applications are typically of small group size, slow group membership dynamics, and awareness of participants\u27 identities and locations. Moreover, they usually consist of several components such as audio, video, shared whiteboard, and single user application sharing engines that collectively help make the collaboration session successful. Each of these components has its demands from the communication layer that may differ from one component to another. This dissertation identifies the overall characteristics of multimedia collaborative applications and their individual components. It also determines the service requirements of the various components from the communication layer. Based on the analysis done in the thesis, new techniques of multicast services that are more suitable for multimedia collaborative applications are introduced. In particular, the focus will be on multicast address management and connection control, routing, congestion and flow control, and error control. First, we investigate multicast address management and connection control and provide a new technique for address management based on address space partitioning. Second, we study the problem of multicast routing and introduce a new approach that fits the real time nature of multimedia applications. Third, we explore the problem of congestion and flow control and introduce a new mechanism that takes into consideration the heterogeneity within the network and within the processing capabilities of the end systems. Last, we exploit the problem of error control and present a solution that supports various levels of error control to the different components within the collaboration session. We present analytic as well as simulation studies to evaluate our work, which show that our techniques outperform previous ones

Management qualitätsbasierter Gruppenkommunikation im Internet

Zugangs- und Nutzungskontrolle bei Unicast bedarf allein der Überwachung am Netzeingang. Diese Arbeit entwirft das Verfahren DSMC (Diffserv Multicast), das die für Multicast zusätzlich benötigte Kontrolle im Netzinneren ergänzt. Es erweitert die Paketweiterleitung (MFC) der Router nur gering und ohne Eingriff in das Multicastrouting, unterstützt so alle Multicastroutingprotokolle des Internets und bietet eine skalierbare Signalisierung zur Steuerung durch zentrales Dienstgütemanagement