This paper endeavors to present a scheme to detect and estimate bottleneck bandwidth along the path in the Internet. We have participated in the RIPE NCC?s TTM project to perform one-way delay (OWD) and loss measurement from a host in our laboratory to other hosts in Europe and USA. TTM is an active measurement system, which has implemented the IPPM one-way delay (RFC2679) and one-way loss metrics (RFC2680). From measured delay, loss, and traceroute?s data, we can know the path properties such as bandwidth, path rerouting, congestion between each host, and so on. Based on measured delay, we propose an algorithm, called Estimating Bottleneck Bandwidth using Packet-pair (EBBP), to estimate bottleneck bandwidth. Our algorithm is based on Bolot?s equation, but we use OWD instead of round trip delay. Every participated host uses GPS receiver to avoid the problem of clock difference. We make phase plot graph from measured delay, extract useful samples, quantize extracted samples, and find intercept of phase plot graph by EBBP. Finally, we can estimate bottleneck bandwidth along the path.