Comparison of TCP Congestion Control Performance over a Satellite Network
Saahil Claypool, Jae Chung, and Mark Claypool
While satellite Internet bitrates have increased, latency can still degrade TCP performance. Realistic assessment of TCP over satellites is lacking, typically done by simulation or emulation only, if at all. This paper presents experiments comparing four TCP congestion control algorithms - BBR, Cubic, Hybla and PCC - on a commercial satellite network. Analysis shows similar steady-state bitrates for all, but with significant differences in start-up throughputs and round-trip times caused by queuing of packets in flight. Power analysis combining throughput and latency shows that overall, PCC is the most powerful, due to relatively high throughputs and consistent, relatively low round-trip times, while for small downloads Hybla is the most powerful, due to fast throughput ramp-ups. BBR generally fares similarly to Cubic in both cases.
Saahil Claypool, Mark Claypool, Jae Chung, and Feng Li. Sharing but not Caring - Performance of TCP BBR and TCP CUBIC at the Network Bottleneck, In Proceedings of the 4th IARIA International Conference on Advances in Computation, Communications and Services (ACCSE), Nice, France, July 28 - August 2, 2019. Online at: http://www.cs.wpi.edu/~claypool/papers/bbr/
Feng Li, Jae Won Chung, Xiaoxiao Jiang, and Mark Claypool. TCP CUBIC versus BBR on the Highway, In Proceedings of the Passive and Active Measurement Conference (PAM), Berlin, Germany, March 2018. Online at: http://www.cs.wpi.edu/~claypool/papers/driving-bbr/