An Early Look at Multipath TCP Deployment in the Wild
Olivier Mehani, Ralph Holz, Simone Ferlin, Roksana Boreli · 2015
Multipath TCP was standardised in 2013 at IETF. It promises better use of network resources of multi-homed devices for capacity aggregation or seamless fail-over capabilities. The uptake has however been rather slow. Some operating systems support MPTCP out of the box, but little is known about their deployment on the server side. We built a scanning infrastructure to search for MPTCP-capable hosts on the Internet. In this study, we used the top-1M Alexa servers to test the platform and gain insight about server support. We find that less than 0.1% of Alexa unique domains and IP addresses currently support MPTCP. Their geographic distribution is quite different from that of clients reported in other studies, with the majority of domains being in China. We also find that very few IPs actually expose multi-homing information, suggesting that these early deployments aim at providing reliability rather than capacity aggregation. We also identify some deployment issues.