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by MertsA 1854 days ago
I just really wish Google would have built QUIC on top of SCTP. They had the clout, and opportunity to push for real end-to-end SCTP support across the internet. Tunnel it over UDP for IPv4 and userspace implementations but use native SCTP where possible like over IPv6 before middleboxes abound that only support TCP, UDP, and ICMP. There's too many NAT implementations, firewalls, etc that don't support SCTP on IPv4 but that's not set in stone for IPv6 yet.

SCTP would have been great for all sorts of applications other than QUIC too. It's got built in multihoming for seamless handoff in mobile environments to keep a persistent connection across e.g. WiFi and cellular. Want multiple streams with no HoL blocking? SCTP is message based and can deliver multiple "streams" simultaneously over a single connection and you get free message boundaries to boot instead of just a plain stream like TCP. Want unordered datagrams? It's got that too. Even partial reliability for a subset of messages in a connection, i.e. reliable metadata for an unreliable live low latency video stream. The four way handshake also basically eliminates the potential impact of a SYN flood.
2 comments
rini17 1854 days ago
They wanted a protocol as opaque to middleboxes as possible. SCTP probably isn't, that was not an issue back when it was created.
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ikiris 1854 days ago
Most of the point is removing round trips from setup. SCTP doesn't do that.
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ldng 1854 days ago
What Google wants for itself should be irrelevant to the broader Inter-Network standards.
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detaro 1854 days ago
Plenty other people and organizations want that too. QUIC at IETF was far from just Google doing something, and large parts of the relevant communities agree on the middlebox issue, people pushing "but we need to be able to mess with traffic!!!" are luckily waay in the minority there.
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adrianmonk 1853 days ago
> It's got built in multihoming for seamless handoff in mobile environments to keep a persistent connection across e.g. WiFi and cellular.

From what I can tell from the QUIC RFC, it also supports this. See section 9, "Connection Migration" (https://www.rfc-editor.org/rfc/rfc9000.html#name-connection-...).

When your phone or whatever switches network, it can initiate a connection migration. Assuming it's the client, which would be the common case.

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