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Modeling and Analysis of Triple Play Services in Multimedia Internet - Keynote speach by prof. Udo Krieger

Udo R. Krieger
Professor at the University of Bamberg, Germany

Tien Van Do
Department of Telecommunications, Budapest University of Technology and Economics, Hungary

Natalia Markovich
Institute of Control Sciences, Russian Academy of Sciences, Russia

Slides

The key-note slides in pdf format

Abstract

In recent years, multimedia Web and real-time applications such as Skype, YouTube, Facebook, Zattoo, PPLive, or World-of-Warcraft supporting voice-over-IP (VoIP), video-ondemand (VoD), live-streaming of videos, IPTV and multi-party on-line game playing have created a rich set of fast growing services in multimedia Internet. They are enabled by new portals featuring Web2.0 and peer-to-peer (P2P) transport technology. Furthermore, they indicate a way towards next generation networks and substantially contribute to new triple play portfolios of competitive Internet and application service providers. The use of adaptive variable bitrate encoding schemes like iSAC or MPEG-4/AVC and the packet-based transfer of multimedia streams have raised new teletraffic issues regarding traffic characterization, traffic control and the dimensioning of the underlying server and transport infrastructure. It is the main task of such a multi-tier infrastructure comprising application, database and media servers to process efficiently the received media requests of a dynamic client population demanding popular objects from the attached databases and to return the latter quickly by streams of related multimedia messages to all requesting sources.
In our presentation we report on a joint research effort with T. van Do and N.M. Markovich to analyze and model important components of these new multimedia service infrastructures by appropriate teletraffic techniques and new statistical methods.
Following a top-down approach of teletraffic engineering, we first study the session performance of a multi-tier service infrastructure and the access to the multimedia content using an Apache Web server as gateway. In particular, we consider the related software architecture with a non-threaded multi-processing module. Considering the used resource pool of available HTTP service processes, we propose a tractable multi-server model to approximate the performance of its load-dependent dynamic behavior. Secondly, we show how VoD and live-streaming media servers can be modelled by appropriate multi-class loss systems taking into account the selection behavior of customers and the popularity of the selected objects.
Finally, we consider the packetized transport of multimedia streams by overlay networks and present a statistical characterization of the traffic streams following an operational modeling approach. Considering measured traffic of IPTV sessions, video and voice streams and applying results of extreme-value theory, we sketch a versatile methodology for VBR traffic characterization in the presence of non-stationarity and dependence in the data which may generate burstiness, long-range dependence and heavy tailed marginal distributions of the underlying traffic characteristics. Using the bivariate process of inter-arrival times between packets and the packet lengths in combination with a bufferless fluid model, it allows us to derive the capacity required by a packet stream on a virtual link, to determine the loss characteristics of the flow and to provide indicators on the user’s satisfaction. Finally, some open issues regarding the characterization and control of multimedia traffic in future Internet are pointed out.

About the Author

Udo Krieger is head of the computer networks group at the Faculty Information Systems and Applied Computer Science of Otto-Friedrich University Bamberg. He has graduated from Technische Hochschule Darmstadt, Germany, receiving an M.Sc. degree in Applied Mathematics and a Ph.D. degree in Computer Science, respectively. Before joining Otto- Friedrich University in 2003 he has been working for 18 years as a senior scientist and technical project manager at the Research and Technology Center of Deutsche Telekom inDarmstadt. From 1994 until 2003 he has also been affiliated as a lecturer to the Computer Science Department of J.W. Goethe University, Frankfurt.
Udo Krieger was responsible for the participation of Deutsche Telekom in the EU projects COST 257, 279 and Eurescom P1112. From 2003 until 2008 he has served as workpackage leader of the activity ”IP Traffic Characterization, Measurements and Statistical Methods” in the IST-FP6 NoEs EuroNGI/EuroFGI. Currently, he is engaged in the ESF action COST IC0703 ”Data Traffic Monitoring and Analysis (TMA): theory, techniques, tools and applications for the future networks” (www.tma-portal.eu/).
Udo Krieger is a member of the editorial board of ”Computer Networks” (www.elsevier.com/locate/comnet) and has been serving in numerous programme committees of international conferences dealing with Internet research including Infocom ’98 and Infocom 2007. His research interests include traffic management of wired and wireless IP networks, teletraffic theory, and numerical solution methods for Markov chains.

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