On 9/30/2022 4:30 PM, Randy Armstrong (OPC) wrote:
* Sure, we could design a presentation layer on top of QUIC. I think it is
better to design a transport/presentation layer for the problem space and then
see how we might make use of QUIC.
Not quite sure why you make a big deal about this. OPC UA supports the kinds of
operations you described but the complex operations are broken into multiple
request-response pairs for transport. All OPC UA needs is a full duplex channel
that allows responses to be returned in any order. I would imagine that any
other protocol built on QUIC would do the same.
That's exactly the way DNS over QUIC is designed. Full duplex channel
(QUIC connection) allowing for series of transactions. Each transaction
request (from the client) is mapped to a new duplex stream stream;
response come back on the reverse part of that stream; responses to
transactions arrive in any order.
The important question is: does QUIC have any inherent limitations that would
make it difficult to implement complex operations over top of QUIC?
No.
You have to pay attention to the management of connections, how to
resume connections after they break, etc. But that's pretty standard
when designing a distributed application.
-- Christian Huitema
