An active queue management scheme to contain high bandwidth flows at a congested router

Abstract

Incorporating mechanisms in the router to enable end-to-end congestion control is important in order to prevent the network collapse. Routers should be able to recognise misbehaving flows and penalise them. In this thesis, we propose a queue management scheme that is based on partial state. It empowers the routers to contain high bandwidth flows at the time of congestion. The scheme maintains an LRU cache at the routers to record information about the high-bandwidth flows. This can be incorporated in RED, an active queue management scheme. The proposed scheme possesses all the advantages of RED. In addition, it lowers the drop rates of short-lived flows and also those high bandwidth flows that reduce their sending rate when congestion is indicated, by use of preferential dropping policies. It is shown by means of simulations that the method is effective in achieving the objective. The overhead involved is low and the operations incur O(1) cost per packet.