A system for and method of actively running performance tests is presented. The system and method allow a device connected, via a VPN or IPSec tunnel, to a VoIP or other service provider network, to run network performance tests using the IP address assigned by a VPN concentrator. The device utilizes the IP address assigned by the VPN concentrator as a means for performing loopback testing. These performance tests characterize the connectivity of the network. Systems and methods then use this characterization to do call admission control, traffic shaping or prioritization.