Wireless mesh network(WMN) is a new multi-hop network for broadband accessing to internet.However,there exists a server unfairness problem based on different hop distances in WMN.To solve this problem,the unfairness issue was analyzed in test-bed experiment and NS2 simulation.A dynamic queue management scheme E-QMMN was proposed,which allocates the queue buffer according to the hop distance of every flow.The experimental results show that the proposed scheme can not only increase the hop distance fairness of the legacy scheme at most 50%,but also reduce the average round trip time at least 29% in congested WMN environments.
The conservative Additive Increase Multiplicative Decrease mechanism of traditional TCP causes the link under-utilization in the Wide Area Networks(WANs) due to the WANs' intrinsic nature of high latency and high packet loss.To alleviate the problem,we present the design and implantation of STAG,an Acceleration Gateway with Split-TCP in the paper.STAG is built on embedded network equipment and acts as a transparent proxy.In STAG,a new improved congestion control method named Rapid TCP is adopted,which determines whether or not to decrease the congestion window based on the packet loss trend.In particular,in the fast recovery phase,it chooses different window adjustment strategies based on the current size of congestion window to achieve higher utilization.The performance validation of STAG is done on both our emulation testbed and the real wide area network.The results show that STAG with Rapid TCP effectively adapts to the high loss network environment and significantly speeds up the applications without loss of fairness.
