[dingosity]

UDP is not required for real-time communication. I have 5k+ concurrent channels of RTP over TLS (not DTLS) going most of the day. If you solved a throughput problem by switching from TCP to UDP, it means you had a middle-box doing bad things.

TCP is not slow unless you encounter congestion or packet loss. But you have to deal with those problems if you're sending data over UDP.

When I was at Linden, we activated fast start and bic on ADITI when testing OGP and Assets over HTTP and things worked MUCH BETTER.

[rlonn]

OTOH, limited congestion and packet loss do not affect things much if you have UDP-based event/object updates. With TCP there there is no way to avoid latency due to head-of-line congestion, but with UDP you just drop a message and move on.

I think TCP works reasonably well today because the network is better and there is often very little packet loss, but as soon as you get some, TCP will optimise for throughput, like designed and at the expense of latency.

[dingosity]

You should read about BIC.