Tangencial, but that's also the reason QUIC (used by HTTP/3) was built upon UDP.
Wasn't it used to avoid head of line blocking?
Built over UDP rather than directly over IP. Introducing a new layer 4 protocol on the internet is not realistic for the foreseeable future.
Re:Linux Kernel MultiPath TCP Project
by londons_explore on Sunday October 16, 2022 @10:31AM
(#33223864)
I think the real answer is to test a lot of middleboxes, come up with some fallback behaviour that will at least work with 99% of them, and then just break the last 1%.
The same happened with Max Segment Size detection - and that mostly works now.
Suppose for example there's a packet-sniffing security appliance along the path, and it only sees packets on one path of the MPTCP flow, and it says "This stream of packets doesn't look like a legitimate TCP flow, so it's probably an attack, so I'll block it."