The Virtue of Gentleness: Improving Connection Response Times with SYN Priority Active Queue Management

To address the issue of long delays caused by excessive buffers in the network, several Active Queue Management policies have been developed in the past five years. However, while these schemes efficiently reduce latency related to bufferbloat, the long delays resulting from the loss of a packet during the establishment or the termination of a TCP connection are usually only considered in more complex solutions relying on Fair Queuing. We have analyzed network traces to get insight into this problem and observed that there are many more losses during the handshake than for the remainder of the data exchange. To solve this problem, we propose SPA (SYN Priority Active queue management), a new low-complexity queue management scheme that combines the benefits and simplicity of the most recent AQM schemes while achieving performance comparable to more complex combinations of fair queueing and AQM.