Traffic Measurement on the Internet presents several novel online measurement methods that are compact and fast. Traffic measurement provides critical real-world data for service providers and network administrations to perform capacity planning, accounting and billing, anomaly detection, and service provision. Statistical methods play important roles in many measurement functions including: system designing, model building, formula deriving, and error analyzing. One of the greatest challenges in designing an online measurement function is to minimize the per-packet processing time in order to keep up with the line speed of the modern routers. This book also introduces a challenging problem - the measurement of per-flow information in high-speed networks, as well as, the solution. The last chapter discusses origin-destination flow measurement.