Network management for providing and managing Quality of Service (QoS) in converged networks, and particularly management of bursty, short-lived data loads, in an opaque network where knowledge of or control over network elements is not required. Preferential treatment is provided to some subset of the network users that require better QoS assurances from the underlying network by applying probabilistic admission control decisions in conjunction with estimated network state provides improved performance for high priority data with bursty data loads.