Avoiding useless packet transmission for multimedia over IP networks: the case of multiple multimedia flows

In this paper, we investigated UPT avoidance problem with multiple multimedia flows. We propose a management module, called Unintelligible Flow Management (UFM), to enhance UPTA in networks with multiple multimedia flows. We have proposed two different management policies for UFM, i.e. Random Select (RS) and Least Bandwidth Select (LBS). We have demonstrated incorporation of RS/LBS into WFQ, and evaluated the effectiveness of both RS and LBS under various network scenarios (e.g. single/multiple congested links, homogeneous/heterogeneous video applications, etc.). Simulation results show that UFM can significantly improve TCP throughput and average video intelligibility index, as compared with plain WFQ. On the other hand, our simulation results also suggest that RS and LBS have similar performance with homogeneous multimedia applications. However, with heterogeneous multimedia applications, LBS yields better performance, in terms of total number of video flows recovered and average intelligibility index of video applications.