QUIC support in Network framework in iOS 15 and macOS 12 seems to be aware of the datagram draft, but there doesn’t seem to be any way to configure NWProtocolQUIC.Options to set the datagram transport parameter (0x20).
If I configure the server to send a datagram to a Swift client, it closes the connection with a PROTOCOL_VIOLATION frame with the error message "DATAGRAM frame size too big".
Given that Eric Kinnear at Apple is an author of the datagram draft, is support for this intentionally missing?
https://www.ietf.org/archive/id/draft-ietf-quic-datagram-03.html
You can see a minimal example here: https://github.com/alta/swift-quic-datagram-example
Thanks!