7 ms·

MPTCP is a drop-in replacement -- but its original designers were paranoid about e.g. packet-sniffing middleboxes, so they made it opt-in. Suppose for example

MPTCP is a drop-in replacement -- but its original designers were paranoid about e.g. packet-sniffing middleboxes, so they made it opt-in. 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."

pid-1 4y ago
Tangencial, but that's also the reason QUIC (used by HTTP/3) was built upon UDP.
- usrnm 4y ago
  Wasn't it used to avoid head of line blocking?
  - tracnar 4y ago
    Built over UDP rather than directly over IP. Introducing a new layer 4 protocol on the internet is not realistic for the foreseeable future.
londons_explore 4y ago
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.