Accurate network bandwidth measurement is important to a variety of network applications. Unfortunately, accurate bandwidth measurement is difficult. We describe some current bandwidth measurement techniques: using throughput, pathchar [8], and Packet Pair [2]. We explain some of the problems with these techniques, including poor accuracy, poor scalability, lack of statistical robustness, poor agility in adapting to bandwidth changes, lack of flexibility in deployment, and inaccuracy when used on a variety of traffic types. Our solutions to these problems include using a packet window to adapt quickly to bandwidth changes, Receiver Only Packet Pair to combine accuracy and ease of deployment, and Potential Bandwidth Filtering to increase accuracy. Our techniques are are at least as accurate as previously used filtering algorithms, and in some situations, our techniques are more than 37% more accurate.