Packet scheduler , Path Manager and Congestion Control

[nishisahu]

what are the current Packet Scheduler , Path Manager and Congestion Control available in MPTCP in the latest linux kernel version . If possible can you give changes in MPTCP in linux kernel version 5.19 and the linux kernel version 6.2 or latest 6.4.1.
As I am working under MPTCP project so I need this information.

[matttbe]

Hi Nishi,

You can find most answers in our wiki.

In short:

• path manager:
  • in-kernel (default)
  • userspace (enabled via sysctl -w net.mptcp.pm_type=1)
• packet scheduler:
  • in-kernel (default)
  • nothing else for the moment, it is in development
• congestion control:
  • no coupled congestion control in the upstream kernel, the ones from TCP are used per subflow.
• the changelog is in our wiki
• we recommend to always use the last stable version (or at least the last LTS one)

I guess I can close this ticket but feel free to re-open it if needed.

[abhinaba-fbr]

Hello @matttbe, I see, several commits for mptcp bpf schedulers (bpf_rr, bpf_red, bpf_first). Are those schedulers have been completly developed? If so, how can we configure to use them in the development-repo kernel built?

[matttbe]

Are those schedulers have been completly developed?

In short: no. These are just some "toys" to help developing the infrastructure. They don't support all cases and more work is still needed, see #350.

If so, how can we configure to use them in the development-repo kernel built?

If you want to contribute to the MPTCP BPF packet schedulers, you will need to compile the kernel yourself and then compile the BPF selftests (cd tools/testing/selftests/bpf && make).

More explanations are available there: #336 (comment) (see the replies below)