Communication Networks Laboratory projects

Network traffic


In general, we are interested in investigating and understanding the importance of traffic characteristics for optimizing network behavior and for improving network's utilization. Our research projects in the Communication Networks Laboratory at the School of Engineering Science at SFU deal with high-speed packet networks. The projects include characterization and modeling of traffic in high-speed networks, simulation and analysis of loss and delay performances in packet networks, simulation of call admission and congestion control algorithms, and the application of intelligent control to communication systems.
Objective of research:
The objective of my research is to characterize, model, and analyze traffic that is collected and measured from high-speed communication networks. We utilize traces that have been collected by our industrial collaborators (Telus Mobility), or that have been collected by other researchers and made available through the Internet. Of particular interest is the analysis of collected data, which involves new statistical approaches and the search for traffic invariants such as self-similarity and long-range dependencies, as well as the understanding of underlying dynamical behavior of the complex system represented by collected data.

Scientific approach:
Traditional queuing theory techniques based on Poisson traffic models were essential for the development of telephone networks. Today's multimedia applications produce complex traffic patterns that result from the statistically multiplexed data, voice, image, and video patterns. For networks carrying such diverse applications, traditional traffic models have proved inadequate and incapable of capturing essential characteristics of the traffic patterns. In such an environment, computer simulation and empirical techniques have begun to play an important role in designing current and future networks. We use hardware and software tools to capture traffic patterns from local and wide area networks, and We utilize modern statistical tools and techniques to characterize collected data.

Novelty of research:
Internet traffic characterization work has only recently been shown to be promising due to the presence of the traffic ``invariants'' detected in traffic traces. Even with the availability of the emerging traffic models, it is not yet known what impact these will have on designing and provisioning data networks, and on selecting optimal connection admission and congestion control algorithms. The goal of my research is to answer some of these questions.

Significance:
The essential difference between traditional traffic modeling and the self-similar models has practical implications for the engineering of communication networks (buffer requirements in routers, Web servers, admission and congestion control algorithms, traffic management, and Quality of Service requirements). Other important areas that may benefit from reliable and meaningful traffic traces are novel pricing policies and tariffing strategies for existing and future Internet services.


Ljiljana Trajkovic, ljilja at cs.sfu.ca.
Last updated Tuesday October  1 22:11:05 PDT 2002.