Research On Active Queue Management

Traditional best-effort service model in IP networks has brought great success to the Internet, if controlled and provisioned appropriately, this model will still be able to satisfy the majority of popular applications in the future. It is necessary to use Active Queue Management mechanism in IP transportation to improve end-to-end performance. Solutions to several problems in these service models are presented in this paper.Unresponsive or TCP-unfriendly flows beget unfair services in best-effort networks, and a number of per-flow scheduling or per-flow dropping mechanisms have been proposed. They all have their own success and failure. In this paper, we propose a fair queuing algorithm that combines active queue management algorithm, using feedback affect to IP transmission on packet dropping in RED algorithm, realize different service class on one link.The Core-Stateless Fair Queuing algorithm is a routing mechanism designed to achieve fair bandwidth allocation with minimal implementation complexity. But there are still several possibilities for improving CSFQ. In this paper, we present a new algorithm, which combined CSFQ with FIFO. This algorithm improves the performance of CSFQ at some aspects such as throughput yet still achieves approximately bandwidth allocation. It decreases the transfer delay and uses the bandwidth more efficiently. Especially, it improves the performance efficiently for short flow and burst flow.We studied some flow-rate estimation algorithms, which were widely implemented for various applications. By comparing the performance among these algorithms from several aspects, we present a new rate estimation algorithm, which considers the direction of the rate changes while estimating the flow-rate. This algorithm increases the availability of the rate estimation algorithm in some aspect by the parameter settings.Active queue management is restricted by the service function that the queue management and buffer management of routers provides. In this paper, we propose a mechanism that use "virtual address" to expand address space, then make queue management apart from buffer management, enrich the function that the routers alter the queue, to adapt to new active queue man-agement mechanism's needs.