Enhanced token bucket policer using reduced fair queuing for Ethernet access networks

An enhanced traffic policer capable of adaptive rate control to provide fair distribution of available network bandwidth is proposed. The policer also performs maximum rate control, limiting flow's use of network resources within a pre-defined bound. Since the enhanced policer is based on a token bucket policer, a flow is guaranteed to receive service at its reserved rate. The proposed policer partially employs a reduced fair queuing algorithm, which is designed for adaptive rate control based on the perceived traffic congestion level. The adaptive rate control requires measurement of the congestion level, which is approximated through examination of local buffer usage. As a result, the allocated service rate increase provided to the flows by the policer is inversely proportional to the network congestion level. In addition, far-travelling flows in multi-hop networks receive the same service rate enhancements as short-travelling flows. The proposed scheme is useful in Ethernet networks, especially access networks, where quality of service is not well organised.