Multipath TCP packet out-of-order

Question

I heard that packet reordering problem is major reason to reduce performance

Packet out-of-order problem is more serious when sub-flows latency is severely different.

But when I see MPTCP with uncoupled congestion control, performance doesn't decrease. When I using uncoupled congestion control, out-of-order doesn't reduce the performance?

Answer 1

uncoupled congestion control doesn't relax the constraints about in-order MPTCP level problems: once segments arrive at the receiver, they must be sent to the application in-order. Maybe you see less of a difference because you get more bandwidth as uncoupled is more aggressive.