STAB is a new active probing tool for locating thin links on a network path. A thin link is a link with less available bandwidth than all links preceding it on the path. The last thin link on the path is the link with the minimum available bandwidth or tight link. STAB combines the concept of "self-induced congestion", the probing technique of "packet tailgating", and special probing trains called "chirps" to efficiently locate the thin links.