Great question — answering as the UphillTech team:
There aren't TCP variants; there are TCP congestion control algorithms : sysctl net.ipv4.tcp_congestion_control cat /proc/sys/net/ipv4/tcp_congestion_control The default is usually cubic or reno , although plenty others are available, and programs can set the preferred algorithm for individual connections (e.g. Transmission enables lp if available). (The same knob affects both IPv4 and IPv6, despite its name.)
Full answer by grawity: https://superuser.stackexchange.com/a/992958 (CC BY-SA 3.0).
Need it done for your business? UphillTech.
