Buffer Management Schemes for Enhanced Tcp Performance over Satellite Links
Sonia Jain, Eytan Modiano · 2006
We designed queue management policies to enhance the performance of TCP over satellite networks. Our queue management schemes, smallest window first (SWF) and smallest sequence number first (SSF) give priority to sessions that have just opened or traveled across lossy and high delay channels. Thus, they combat the inherent unfairness of TCP. Our protocols help slow sessions grow their congestion windows more rapidly and effectively compete against other sessions for bottleneck resources. Although our protocols are useful in other contexts, they are particularly useful in satellite networks. With their high round trip times (RTTs), sessions can be severely penalized by the closure of the TCP congestion window. We show that our schedulers not only provide increased fairness, but they also substantially reduce the latency associated with transmitting short files (e.g., e-mails). SWF doubles the goodput of lossy sessions over FIFO and provides a 16% improvement over DRR. It also reduces the latency of short file transfers up to 40% over DRR.