This is a one year project to generate software and a pilot infrastructure for measuring Internet performance. The project could lead to positioning probe machines throughout the Internet to collect data to assist in identifying current and long-term performance characteristics of portions of the Internet and the overall system. The project is patterned after Network Probe Daemon (NPD), a prototype by one of the co-PIs which instrumented 37 Internet sites to perform the first large-scale measurements of end-to-end Internet behavior regarding routing and connection dynamics. This project also will establish the framework for producing a national Internet profile to record the network's performance over time.