Adaptive marking threshold for improving bandwidth assurance in a differentiated services network

Recent research studies have shown that assured forwarding (AF) service in the current differentiated services (Diffserv) framework does not provide bandwidth assurance in some circumstances. This paper proposes an adaptive marking threshold mechanism, called adaptive CIR threshold (ACT), which aims to improve bandwidth assurance for aggregate flows sharing the same AF class only based on local knowledge. Extensive simulation results demonstrate significant improvement with ACT in bandwidth assurance under various conditions: different round trip times (RTT), different numbers of micro-flows in an aggregate, different target rates, different packet sizes, and the presence of non-adaptive flows, compared with earlier mechanisms proposed in the literature.