A Feedback based Probability Selection for Frame forwarding in AVB switched Ethernet

In order to support real-time quality of service in time-sensitive and time-tolerant coexisting network in Ethernet, a set of IEEE standards for transporting and forwarding real-time content over Ethernet are proposed that known as Audio Video Bridging (AVB). By bandwidth reservation and priority isolation, AVB traffic are re-mapped into the highest Ethernet frames and are always prior forwarding, so the time delay can be ensured in the specific scope. However, the time-tolerant traffics are simply crude treated by Strict Priority (SP) selection and Best Effort (BE) forwarding. The consequence is that the lowest priorities are over-sacrificed when the bandwidth is limited. In this paper, we proposed a FeedBack based Probability Selection (FBPS) for frame forwarding to enforce a proportional queuing delay. By means of changing the probability of BE traffics been selected, the average queuing delay ration can be controlled in a fixed value. Which ensure high priority BE traffics can enjoy a relatively low latency, and low priority BE can also be operated as well. The experiment demonstrates the effectiveness of FBPS.