A guaranteed minimum throughput service for TCP flows using measurement-based admission control

We propose a new scheme for a network service that guarantees a minimum throughput to flows accepted by admission control (AC). The whole scheme only uses a small set of packet classes in a core-stateless network. At the ingress of the network each flow packet is marked into one of the sets of classes, and within the network, each class is assigned a different discarding priority. The AC method is based on edge-to-edge per-flow throughput measurements using the first packets of the flow, and it requires flows to send with a minimum rate. We evaluate the scheme through simulations in a simple bottleneck topology with different traffic loads consisting of TCP flows that carry files of varying sizes. We use a modified TCP source with a new algorithm that forces the source to send with a minimum rate. We compare our scheme with the besteffort service and we study the influence of the measurement duration on the scheme's performance. The results prove that the scheme guarantees the requested throughput to accepted flows and achieves a high utilization of network resources. Copyright (c) 2006 John Wiley & Sons, Ltd.