MMBnet 2017 - Proceedings of the 9th GI/ITG Workshop „Leistungs-, Verlässlichkeits- und Zuverlässigkeitsbewertung von Kommunikationsnetzen und Verteilten Systemen“

Nowadays, mathematical methods of systems and network monitoring, modeling, simulation, and performance, dependability and reliability analysis constitute the foundation of quantitative evaluation methods with regard to software-defined next-generation networks and advanced cloud computing systems. Considering the application of the underlying methodologies in engineering practice, these sophisticated techniques provide the basis in many different areas. The GI/ITG Technical Committee “Measurement, Modelling and Evaluation of Computing Systems“ (MMB) and its members have investigated corresponding research topics and initiated a series of MMB conferences and workshops over the last decades. Its 9th GI/ITG Workshop MMBnet 2017 „Leistungs-, Verlässlichkeits- und Zuverlässigkeitsbewertung von Kommunikationsnetzen und Verteilten Systemen“ was held at Hamburg University of Technology (TUHH), Germany, on September 14, 2017. The proceedings of MMBnet 2017 summarize the contributions of one invited talk and four contributed papers of young researchers. They deal with current research issues in next-generation networks, IP-based real-time communication systems, and new application architectures and intend to stimulate the reader‘s future research in these vital areas of modern information society

An

QoS

Efficiency of search methods in dynamic wireless networks

Abstract – Search methods in dynamic networks usually cannot rely on stable topology from which shortest or otherwise optimized paths through the network are derived. When no reliable search indices or routing tables are provided, other methods like flooding or random walks have to be considered to explore the network. These approaches can exploit partially available information on network paths, but the search effort naturally increases with the lack of precise paths due to network dynamics. This problem is especially relevant for wireless technology with strict limitation on power consumption. We compare the efficiency of random walks and flooding for exploring networks of small to medium size. Several scenarios are considered including partial path information support for search. Transient analysis and a bound is applied in order to evaluate the messaging overhead. I

The Gilbert-Elliott Model for Packet Loss in Real Time Services on the Internet

Abstract. The estimation of quality for real time services over telecommunication networks requires realistic models in order to generate impairments and failures during transmission. Starting with the classical Gilbert-Elliot model, we derive the second order statistics over arbitrary time scales and fit the parameters to match the packet loss pattern of traffic traces. The results show that simple Markov models are appropriate to capture the observed loss pattern.