Abstract:
Internet coordinate systems embed network metrics such as latencies between Internet nodes into some geometric space so that unmeasured latencies can be estimated using distance computation in that space. Our main observation is that absolute relative error tells us very little about the quality of an embedding as experienced by a user. We define several new accuracy metrics that attempt to quantify various aspects of user-oriented quality. The Triangle Inequality Violations (TIVs) in the Internet latency routes caused by the Internet's routing structure will necessarily degrade the accuracy of any embedding technique. We argue that TIVs should not be treated as measurement artifacts, but rather as natural features of the Internet's routing structure.

Biography of the speaker:
Eng Keong Lua is currently the Special Researcher in the Nippon Telegraph and Telephone Corporation (NTT), NTT Service Integration Laboratories, at Tokyo, Japan. In 2006, he obtained his Ph.D. degree in Computer Science from the University of Cambridge, United Kingdom (UK). He was supported by Microsoft Research Fellowship, Cambridge-MIT Institute, and UK EPSRC e-Science FutureGrid program. In 2004, he had completed a 6-month research internship at the Intel Research, Cambridge, UK. He was the inaugural recipient of the prestigious Australia-Asia Award in 2003, presented by the Australian Government to promising scholars in Asia for sponsorship of research activities in Australia. He received his M.Sc. degree in Telecommunications from the Department of Electronic and Electrical Engineering, University College London (UCL), UK, in 1997, and both Postgraduate Diploma of Teaching in Higher Education and B.A.Sc degree in Computer Engineering from the Nanyang Technological University, Singapore, in 1995 and 1993 respectively.