These are all very good points. In addition: * We really care about on-the-"wire" efficiency. So we like having control over that. * We actually looked very

These are all very good points. In addition: * We really care about on-the-"wire" efficiency. So we like having control over that. * We actually looked very hard at DTLS, and do support it, but it is still optimized for browsers and not devices and as such carries some thought-baggage that is tricky to work around. So DTLS doesn't carry the bulk of our traffic. * IPSec turned out to be impossible to support at the back end. Equipment that supports IPSec tunnel termination often is sold in terms of tens of thousands of tunnel terminations per box. We need tens of millions. That scale does not work for us. We do use it in some specific circumstances though. * Anything that requires TCP is a non-starter as well. Not at all for the same reasons as the QUIC people. The NoTCP joke was really funny to me.