In one embodiment, methods are described to measure bandwidth limits through multiple test sites. A testing quantity of network packets is generated, the network packets are sent through a service provider network to a plurality of receivers at a testing transmission rate that exceeds an upstream transmission rate limit of the service provider network, a report indicating a received number of packets is received from each of the plurality of receivers, and an upstream transmission rate limit of the service provider network is determined based on the testing transmission and the reports. By using multiple test sites, potential bottlenecks at any one test site are reduced. A similar method can be used to calculate a downstream transmission rate limit. Once measured, the bandwidth limits may be used to adjust quality of service on an edge router or compared against a known service level agreement of the service provider network.