Call admission control in generalized processor sharing (GPS) schedulers using non-rate proportional weighting of sessions

Generalized processor sharing (GPS) is an ideal fluid scheduling discipline that supports well defined delay and loss bounds on leaky-bucket constrained traffic. Its packetized versions (WFQ, WF2Q, PGPS etc.) are considered as the packet scheduler of choice in IP routers and ATM switches of the future. The currently accepted approach for the design of GPS schedulers is based on deterministic QoS guarantees, which is overly conservative due to the applied loose bounds and leads to limitations on capacity. We developed a framework for the computation of tighter delay bounds, bandwidth and delay de-coupling in GPS systems. In this paper, we propose several effective call admission control (CAC) algorithms that work in the bandwidth and delay de-coupled system while using the tighter delay bounds presented herein. One of the proposed CAC algorithms also handles the best-effort service class beside the QoS guaranteed service classes. Performance evaluation of several CAC algorithms are presented