Methods and apparatus are provided for QoS-based admission control (QBAC). The disclosed QoS-based admission control techniques use QoS parameter measurements. An admission control request for a call on a path in a packet network is processed by obtaining performance data for the path; and predicting a performance of the call on the path using performance data for the path. In one implementation, the predicted performance is based on one or more derivatives of the performance data. Typically, the performance data includes historical performance data and is based on at least one quality of service metric.