[thickice]

Why doesn't QUIC work well for machine-to-machine traffic ? Is it due to the lack of offloads/optimizations for TCP and machine-to-machine traffic tend to me high volume/high rate ?

[yello_downunder]

QUIC would work okay, but not really have many advantages for machine-to-machine traffic. Machine-to-machine you tend to have long-lived connections over a pretty good network. In this situation TCP already works well and is currently handled better in the kernel. Eventually QUIC will probably be just as good for TCP in this use case, but we're not there yet.

[jabart]

You still have latency, legacy window sizes, and packet schedulers to deal with.

[extropy]

The NAT firewalls do not like P2P UDP traffic. Majoritoy of the routers lack the smarts to passtrough QUIC correctly, they need to treat it the same as TCP essentially.

[beeflet]

NAT is the devil. bring on the IPoc4lypse

[johncolanduoni]

QUIC isn’t generally P2P though. Browsers don’t support NAT traversal for it.

[dan-robertson]

I think basically there is currently a lot of overhead and, when you control the network more and everything is more reliable, you can make tcp work better.

[m00x]

It's explained in the reddit thread. Most of it is because you have to handle a ton of what TCP does in userland.

[exabrial]

For starters, why encrypt something literally in the same datacenter 6 feet away? Add significant latency and processing overhead.

[sleepydog]

Encryption gets you data integrity "for free". If a bit is flipped by faulty hardware, the packet won't decrypt. TCP checksums are not good enough for catching corruption in many cases.

[mschuster91]

Because any random machine in the same datacenter and network segment might be compromised and do stuff like running ARP spoofing attacks. Cisco alone has had so many vendor-provided backdoors cropping up that I wouldn't trust anything in a data center with Cisco gear.

[lll-o-lll]

To stop or slow down the attacker who is inside your network and trying to move horizontally? Isn’t this the principle of defense in depth?

[20k]

Because the NSA actively intercepts that traffic. There's a reason why encryption is non optional

[switchbak]

Service meshes often encrypt traffic that may be running on the same physical host. Your security policy may simply require this.