NICHOLAS G DUFFIELD email: duffield@research.att.com 180 PARK AVE - BUILDING 103 FLORHAM PARK, NJ, 07932

Publications

A complete list of publications is here. Partial indices in DBLP, MathSciNet,

What I do

I am a Distinguished Member of Technical Staff in the Internet and Network Systems Research Laboratory at AT&T Labs-Research in Florham Park, New Jersey. I am an AT&T Fellow and an IEEE Fellow, and a member of the Editorial Board of the IEEE/ACM Transactions on Networking.

I work on measurement, inference and analysis of traffic and performance in the internet, including:

• Traffic Sampling: I am an inventor of the Smart Sampling methods that underpin AT&T's Traffic Analysis Service, and of Trajectory Sampling, which will enable new classes of measurement applications. I helped start the Packet Sampling (PSAMP) working group in the Internet Engineering Task Force, and was its first chair.
• Network Tomography: correlating network measurements to infer what can't be measured diriectly. The main applications are inference of traffic matrices (a.k.a. Tomo-Gravity) and of network performance.
• Active Measurement: (i) tailoring probe streams to reveal the dynamics of network congestion, and (ii) tailoring probing paths in order to to focus on the performance of customer traffic paths.
• Attack Detection: network measurement infrastructures generate enormous volumes of data.  Adaptive aggregation techniques reduce data volumes while retaining detail for heavy hitters (PANIC). Routine stress testing of traffic aims to help identify misbehaving traffic. Detection sensitivity can be adapted to the ambient intensity of attacks in order to minimize the cost of errors in identifying attacks.

My Background

I receved a B.A. in Natural Sciences (in 1982) and the Certificate of Advanced Study in Mathematics (in 1983) from the University of Cambridge, U.K, and a Ph.D. in Mathematical Physics (in 1987) from the University of London, U.K. I held post-doctoral and faculty positions in Dublin (and here, and here) and Heidelberg before moving to AT&T in 1995. I worked in mathematical physics until the early 90's, then found applications of some of its methods to queueing theory, which got me started in networking...

My Projects
	Harbinger : Agile Network Monitoring
	Tomo-gravity : Traffic Matrix Inference
	Trajectory Sampling (TS)
	Adaptive Defense : Optimal Use of Available Sensors, Actuators
	Stress Testing: Inferring Traffic Legitimacy Through Selective Impairment
	PANIC : Scalable Heavy Hitter Detection
	Smart Sampling : Accurate Sampling of Flow Records
	Network Performance Tomography
	Badabing: Probing the Structure of Network Congestion

My Patents
	7536455	Optimal combination of sampled measurements, 05-19-2009
	7508769	Consistent sampling for network traffic measurement, 03-24-2009
	7437385	Methods and apparatus for detection of hierarchical heavy hitters, 10-14-2008
	7299283	Apparatus for size-dependent sampling for managing a data network, 11-20-2007
	7293086	Traffic matrix estimation method and apparatus, 11-06-2007
	7197048	Virtual private network, 03-27-2007
	7080136	Method and apparatus for size-dependent sampling for managing a data network, 07-18-2006
	6912232	Virtual Private Network, 06-28-2005
	6873600	Consistent sampling for network traffic measurement, 03-29-2005
	6452933	Fair queuing system with adaptive bandwidth redistribution, 09-17-2002
	6310857	Method and apparatus for smoothing and multiplexing video data flows, 10-30-2001