Node: TCP Fast Open

[jannicars]

• Version: 6.3.1
• Platform: Windows 64 Bit
• Subsystem: net

Hello,

Is it possible to add TCP Fast Open to the TCP Net Module?

[bnoordhuis]

It's not completely out of the question but what is your use case for it?

An argument against is that it's only supported by a handful of platforms (and at that only recent versions, Linux 3.7, OS X 10.11 and Windows 10.)

[jasnell]

Agreed. It's one of those things that would be certainly nice to have in theory but it's not clear just how extensively it's supported or used in the wild. Having clear use cases would help.

[ewindisch]

This would be awesome. I have a strong use-case for this where we're sometimes connecting to an API rapidly, but some clients may only infrequently access. For architectural reasons It would be bad for us to maintain a TCP connection. We can use TCP Fast Open to reduce round-trips when re-establishing this connection. (We control client and server, so questions of extensive support is not a problem for us)

[santigimeno]

FWIW there's a WIP PR in libuv

[oerdnj]

Folks, it would be great if you could review my PR in libuv, and try to push it through. I have received a zero response on the PR so far.

[NawarA]

What do we need to do to add this feature? What are the next steps?

[sebdeckers]

This would be great to have. Platform support is extensive today.

@jasnell This should remove 1RTT from HTTP/2 connections with most modern browsers/devices/OSes. Once OpenSSL1.1.1/TLS1.3 lands we'd finally have 0RTT support for HTTP/2.

[oyyd]

shadowsocks, one of the popular proxy tool we use, utilizes TCP fast open to optimize network traffic.

I personally expect this to be implemented.

[niftylettuce]

Would love to see this added, then we can set net.ipv4.tcp_fastopen to 3 in sysctl tuning 👍