MPTCP addresses this, Apple uses it (or used it, I haven't looked in a long time), and there's some way to enable it for applications on their OSes, but you als

MPTCP addresses this, Apple uses it (or used it, I haven't looked in a long time), and there's some way to enable it for applications on their OSes, but you also need to make it work on a server OS... I don't think it's been merged into anything but patches are around.