The first Media over QUIC CDN: Cloudflare

Hi! I have a few :)

How close are we to having QUIC actually usable in browsers (meaning both browsers and infrastructure supports it, and it 'just works')

How does QUIC get around the NAT problem? WebRTC requires STUN/TURN to get through full cone NAT, particularly the latter is problematic, since it requires a bunch of infra to run.

Chrome and Firefox support WebTransport. Safari has announced intent to support it and they already use QUIC under the hood for HTTP/3.

Cloud services are pretty TCP/HTTP centric which can be annoying. Any provider that gives you UDP support can be used with QUIC, but you're in charge of certificates and load balancing.

QUIC is client->server so NATs are not a problem; 1 RTT to establish a connection. Iroh is an attempt at P2P QUIC using similar techniques to WebRTC but I don't think browser support will be a thing.

QUIC is already quite widely used! We see close to 10% of HTTP requests using HTTP/3: https://radar.cloudflare.com/adoption-and-usage

As for the NAT problem, that's mainly an issue for peer-to-peer scenarios. If you have a publicly addressable server at one end, you don't need all of the complications of a full ICE stack, even for WebRTC. For cases where you do need TURN (e.g. for WebRTC with clients that may be on networks where UDP is completely blocked), you can use hosted services, see https://iceperf.com/ for some options.

And as for MoQ - the main thing it requires from browsers is a WebTransport implementation. Chrome and Firefox already have support and Safari has started shipping an early version behind a feature flag. To make everything "just work" we'll need to finish some "streaming format" standards, but the good news is that you don't need to wait for that to be standardized if you control the original publisher and the end subscriber - you can make up your own and the fan out infrastructure in the middle (like the MoQ relay network we've deployed) doesn't care at all what you do at that layer.

Last I checked, Iroh is gonna use WebRTC datachannels to run QUIC over SCTP

That is all sorts of miserable. I had an initial prototype that emulated UDP over SCTP, running QUIC (without encryption) on top. The problem is that SCTP becomes the bottleneck, plus it's super complicated.

I immediately jumped ship to WebTransport when Chrome added support. But I suppose there's no other option if you need P2P support in the browser.

Thanks for the answer!

Unfortunately the NAT problem is more common than you think :( Lot's of corporate networks use full cone NAT (I know ours does), and so does AWS (if you don't have a public IP, but go through igw), so some sort of NAT punchthrough seems to be necessary for WebRTC.

I wonder if WebTransport has its own solution to the problem.

But I guess you can always rely on turn - by the way, does MoQ have some sort of ICE negotiation mechanism, or do we need to build that on top?

I answered in another reply, but client -> server protocols like TCP and QUIC don't have an issue traversing NATs. The biggest problem you'll run into are corporate firewalls blocking UDP, but hopefully HTTP/3 adoption helps that (UDP :443, same as WebTransport).

And while WebRTC solves some rather hard problems like P2P transfers, the beauty of DASH is that is can rely on existing servers and clients. So I am also quite puzzled on the comparison. Particularly as the post do not get into much detail on the path forward. I feel sometimes we are rather getting back to an AOL style Internet, that just connects dedicated clients to a CDN.

Safari has it now its behind a flag in the preferences/privacy/advanced/devtools