mptcp causes the network to become very slow

[luochongjun]

In my environment, the A link can get 100M speed
If link B is set to subflow, the speed of link B can be 50M
I can test either link individually to get the correct rate.
Once mptcp was set, I could only get 10M, which confused me.
According to the working goal of mptcp, the rate after using mptcp should not be lower than the optimal one of all links, in my environment, the theoretical throughput should not be less than 100M.

my kernel version is v5.15.127

[matttbe]

Hi @luochongjun

The kernel v5.15 is quite old and a lot of improvements have been done since then (and still more coming). Do you mind re-trying with a client and server running with a more recent kernel? Ideally build the kernel yourself using our export branch or the last stable one (v6.6).

[matttbe]

I suggest closing this old ticket. Feel free to re-open it if you have the same issue with a recent (last stable / LTS) and up-to-date kernel.