Hung X. Nguyen , Research Fellow at  TRC Mathematical Modelling The University of Adelaide Address: TRC Mathematical Modelling, University of Adelaide,  Australia, 5005. E-mail: Hung.Nguyen(AT)adelaide.edu.au Phone: +61 8 8303 6214 Fax:+61 8 8303 4395

Short Biography    Research    Publications  

Short Biography

I am currently a reseacrh fellow at the Teletraffic Research Center at Adelaide University, Australia.

I obtained my PhD in Computer Science and Telecommunications from EPFL in April 2008. My advisor is Professor Patrick Thiran. Prior to that, I received the B.Eng. degree in Information Technology and Telecommunications Engineering from the University of Adelaide, Australia in 2001 and completed the Pre-Doctoral school in communication systems at the Swiss Federal Institute of Technology, Lausanne (EPFL) in June, 2002.
 

CV (pdf)

Research

I am interested in network measurement and tomography, especially in measurement accuracy and the application of Internet tomography for failure diagnosis. One of the weak points of today's Internet is the lack of built-in tools to identify and correct performance anomalies such as routing failures, excessive delays or losses. Calculating link performances at a particular time using end-to-end measurements is called network performance diagnosis ; whereas inferring parameters of the statistical models governing these performances is called network performance tomography. Both network diagnosis and tomography are notoriously difficult because regular unicast data do not provide enough information to allow the identification of the link performances. More specifically, the system of equations relating end-to-end performances with link performances is under-determined and hence has infinitely many solutions.

I study three fundamental questions of Internet tomography and diagnosis using regular unicast probes. First, what is the optimal end-to-end probing strategy for network diagnosis and tomography? Second, how do we overcome the under-determined problem of network diagnosis to accurately troubleshoot performance issues? Third, which statistical properties of network links can be inferred from end-to-end measurements?

Our main methods exploit the spatial and temporal distribution of packet losses on the Internet. Namely, most links on the Internet have negligible loss rates and that links with high loss rates usually also suffer high loss rate variances. Details on theoretical findings and their implementations can be found under the following link.

• IP network monitoring and tomography

I also work on randomized algorithms for overlay routing. We analyze the performance of the famous two random choices method on load balancing overlay networks. We show that the simple two random choices algorithm does not work on many realistic settings and propose modifications to this algorithm that provides guaranteed performance on practical overlays. Latest results can be found under the following link.

• Overlay routing and load balancing

Publications

• H. X. Nguyen, R. Teixaira, P. Thiran and C. Diot, End-to-End Detection of IP Path Failures: Algorithms and Scalability Analysis, to appear in Proc. IEEE Infocom 2009, Rio de Janeiro, Brazil.
• Hung Nguyen and Matthew Roughan, On the Correlation of Internet Packet Losses , in the Australasian Telecommunications Networks and Applications Conference (ATNAC), Adelaide, Australia, Dec. 2008.
• H. X. Nguyen, D. Figueiredo, M. Grossglauser and P. Thiran, Balanced Relay Allocation on Heterogeneous Unstructured Overlays , in Proc. IEEE Infocom 2008, Phoenix, USA.
• H. X. Nguyen and P. Thiran, Network Loss Inference with Second Order Statistics of End-to-End Flows, in Proc. of ACM Sigcomm IMC 2007, San Diego, USA. --- Matlab Code , Data
• H. X. Nguyen and P. Thiran, The Boolean Solution to the Congested IP Link Location Problem: Theory and Practice , in Proc. of IEEE Infocom 2007, Alaska, USA. --- Matlab Code
• H. X. Nguyen and P. Thiran, Using End-to-End Data to Infer Lossy Links in Sensor Networks, in Proc. of IEEE Infocom 2006, Barcelona, Spain. --- Matlab Code
• H. X. Nguyen and P. Thiran, Failure Location in Transparent Optical Networks: The Asymmetry Between False and Missing Alarms, in Proc. of the 19th International Teletraffic Congress (ITC 19), 2005, Beijing, China.
• H. X. Nguyen and P. Thiran, Binary Versus Analogue Path Monitoring in IP Networks, in Proc. of PAM 2005, Boston, USA.
• H. X. Nguyen and P. Thiran, Active Measurement for Multiple Link Failure Diagnosis in IP Networks, in Proc. of PAM 2004, Antibes-Juan les Pins, France.

• O. Dousse, H. X. Nguyen and P. Thiran, Deux applications de processus ponctuels aux reseaux de communication, in Proc. of GRESTI 2005.
• C. Mas, H. X. Nguyen and P. Thiran, Failure Location in WDM Networks , a book chapter in Emerging Optical Network Technologies: Architectures, Protocols and Performance, Springer, 2005.
• H. X. Nguyen, P. Thiran and C. Barakat, On the Correlation of TCP Traffic in Backbone Networks, in Proc. of ISCAS (IEEE International Symposium on Circuits and Systems) 2004, Vancouver, Canada.
• H.Nguyen, D.Abbott, Motion Detection Algorithms Using Insect Vision Template Model, In proceedings of SPIE International Symposium on Electronics and Structures for MEMS II, Volume 4591, Adelaide, Australia 2001.