Ljiljana Trajkovic
Simon Fraser University
Vancouver, Canada
ljilja@cs.sfu.ca
Discovering properties of the Internet topology is important for evaluating performance of various network protocols and applications. The discovery of power-laws and the application of spectral analysis to the Internet topology data indicate a complex behavior of the underlying network infrastructure that carries a variety of the Internet applications. In this paper, we present analysis of datasets collected from the Route Views project. The analysis of collected data shows certain historical trends in the development of the Internet topology. While values of various power-laws exponents have not substantially changed over the recent years, spectral analysis of the normalized Laplacian matrix of the associated graphs reveals notable changes in the clustering of Autonomous System (AS) nodes and their connectivity.
Mining and statistical analysis of network data are often employed to determine traffic loads, analyze patterns of users' behavior, and predict future network traffic. In this talk, we analyze traffic data collected from three deployed networks: a cellular wireless network used by public safety agencies (E-Comm), a satellite network used by Internet service providers (ChinaSat), and the Internet.
We describe analysis of network log data collected from E-Comm, a public safety trunked radio network that utilizes circuit-switched cellular wireless technology. We examine statistical distributions and autocorrelation functions of call inter-arrival and call holding times during busy hours. Our findings indicate that traditional Erlang models used for voice traffic may not be suitable for evaluating the performance of trunked radio networks. We also describe collection of traffic data, characterization of traffic loads, and distribution of packet sizes in ChinaSat, a hybrid satellite-terrestrial system. We investigate long-range dependence as the traffic patterns vary, propose a traffic model for the Transmission Control Protocol (TCP) connections, and use data from billing records to predict future traffic loads. Since discovering network topology is important for analyzing routing protocols and network robustness and resilience, we also examine datasets from the Route Views and RIPE projects and identify important properties of Internet graphs.
Our current traffic measurement project deals with traffic collection from BC.Net, the Vancouver Lower Mainland Gigabit Ethernet network. Data collected from BC.Net will be used to analyze behavior and performance of the Border Gateway Protocol (BGP).
She is currently a Professor in the School of Engineering Science at Simon Fraser University, Burnaby, British Columbia, Canada. From 1995 to 1997, she was a National Science Foundation (NSF) Visiting Professor in the Electrical Engineering and Computer Sciences Department, University of California, Berkeley. She was a Research Scientist at Bell Communications Research, Morristown, NJ, from 1990 to 1997, and a Member of the Technical Staff at AT&T Bell Laboratories, Murray Hill, NJ, from 1988 to 1990. Her research interests include high-performance communication networks, control of communication systems, computer-aided circuit analysis and design, and theory of nonlinear circuits and dynamical systems.
Dr. Trajkovic served as 2007 President of the IEEE Circuits and Systems Society. She was a member of the Board of Governors of the IEEE Circuits and Systems Society (2001 - 2003 and 2004 - 2005). She serves as Vice President Publications of the IEEE Systems, Man, and Cybernetics Society (2010 - 2011) and served as Vice President Long-Range Planning and Finance (2008 - 2009) and as a Member at Large of its Board of Governors (2004 - 2006). She is Chair of the IEEE Circuits and Systems Society joint Chapter of the Vancouver/Victoria Sections. She was Chair of the IEEE Technical Committee on Nonlinear Circuits and Systems (1998). She was Technical Program Co-Chair of ISCAS 2005 and served as Technical Program Chair and Vice General Co-Chair of ISCAS 2004. She served as an Associate Editor of the IEEE Transactions on Circuits and Systems (Part I) (2004 - 2005 and 1993 - 1995), the IEEE Transactions on Circuits and Systems (Part II) (1999 - 2001 and 2002 - 2003), and the IEEE Circuits and Systems Magazine (2001 - 2003). She is a Fellow of the IEEE.