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Department of Informatics - Communication Systems Group

Efficiency and Information Management in Peer-to-Peer Systems

Keynote Speaker: Ralf Steinmetz, Darmstadt University of Technology


In recent years, overlay networks have gained significant attention in both the research community and industry. In current application scenarios of peer-to-peer systems, resource management considerations are limited to reducing the overhead of different types of overlay networks or increasing their routing efficiency. However, when applying overlay networks in critical scenarios with significant scarce resources like emergency response or catastrophe management, a peer-to-peer system has be observed in an integrated way, i.e. considering the overlay network operations as well as the services delivered with the peer-to-peer system. This is even more important when applying the peer-to-peer paradigm in mobile networking environments, as typically required in catastrophe management scenarios. Accordingly, a "combined bandwidth management" over the two distinct functional domains of peer-to-peer systems, the overlay network operations and service delivery, have been identified as a key challenge to overcome in such scenarios.

In this talk we first present HiPNOS.KOM, a priority based scheduling and active queue management system that guarantees better QoS messages of higher priority in upper network layers of peer-to-peer systems. Evaluation using the peer-to-peer simulator PeerfactSim.KOM shows that HiPNOS.KOM brings significant improvement in Kademlia in comparison to FIFO and Drop-Tail, strategies that are currently used on each peer. In Kademlia user initiated lookups have ca. 25% less duration of the operations when using HiPNOS.KOM compared to the regular scheduling environment.

In the second part of this talk, we present ECHoP2P.KOM, a solution for Emergency Call Handling (ECH) for peer-to-peer based VoIP services. Based on Globase.KOM and HiPNOS. KOM, ECHoP2P.KOM provides the functionality to determine the closest, (geographically) responsible Emergency Station for a calling peer. Further, Emergency Calls are processed with highest priority in the overlay, in order to give Quality of Service guarantees. We evaluate ECHoP2P.KOM thoroughly and present a quality and costs analysis, and also identify tradeoffs and effects of optimization parameters. ECHoP2P.KOM provides a fully evaluated solution for Emergency Call Handling and further location-aware applications.

In the final part of this talk we present the concept of a distributed, self-organizing Efficiency and Information Management System (EMS) for peer-to-peer systems. The EMS collects and aggregates information about system components and uses it for analyzing and forecasting the system status using mathematical models. This knowledge can be used by the different functional domains of the peer-to-peer system in order to enable a more efficient resource usage by applying QoS strategies and setting priorities.


Prof. Ralf Steinmetz worked for over nine years in industrial research and development of distributed multimedia systems and applications. He has been head, since 1996, of the Multimedia Communications lab at Darmstadt University of Technology, Germany.

From 1997 to 2001 he directed the Fraunhofer (former GMD) Integrated Publishing Systems Institute IPSI in Darmstadt. In 1999 he founded the Hessian Telemedia Technology Competence Center (httc e.V.). His thematic focus in research and teaching is on multimedia communications with his vision of real "seamless multimedia communications". With over 200 refereed publications he has become ICCC Governor in 1999; was awarded the ranking of Fellow of both, the IEEE in 1999 and the ACM in 2002.

Ralf Steinmetz is co-editor of "Peer-to-Peer Systems and Applications" (Springer, LNCS 3485).

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