Redundant bundling in TCP to reduce perceived latency for time-dependent thin streams

摘要

TCP and UDP are the dominant transport protocols today, with TCP being preferred because of the lack of fairness mechanisms in UDP. Some time-dependent applications with small bandwidth requirements, however, occasionally suffer from unnecessarily high latency due to TCP retransmission mechanisms that are optimized for high-throughput streams. Examples of such thin-stream applications are Internet telephony and multiplayer games. For such interactive applications, the high delays can be devastating to the experience of the service. To address the latency issues, we explored application-transparent, sender-side modifications. We investigated whether it is possible to bundle unacknowledged data to preempt the experience of packet loss and improve the perceived latency in time-dependent systems. We implemented and tested this idea in Linux. Our results show that we can reduce the application latency by trading it against bandwidth.