Hi Rob, On Thu, Jun 30, 2022, at 19:15, Robert Wilton via Datatracker wrote: > (1) The purpose of having a fixed value is to allow QUIC to be > efficiently distinguished from other protocols; > > This sentence seems inconsistent with draft-ietf-quic-manageability that > states > that this bit cannot be used reliably to indicate QUIC traffic.
That appears to be a misreading of the text. The failing here is that this text doesn't say *by whom*. It only refers to RFC 7983[bis]. I thought that was sufficient. Would this be clearer? > The purpose of having a fixed value is to allow endpoints to efficiently > distinguish QUIC from other protocols; [...] Note that this is only *mostly* correct. Endpoints can cooperate with intermediaries to disable this extension if identification or demultiplexing is useful. I believe that this is what Google's current deployment does, for example. That's independent of the RFC 7983-related use, where the same is also possible. > Ultimately, for QUIC, it isn't really clear to me whether: > (i) Intermediates nodes are not expected to be able to efficiently identify > QUIC traffic. (ii) Intermediate nodes are expected to efficiently identify > QUIC > v1 traffic only. > > Assuming that the quic bit grease extension ends up with reasonable deployment > then I think that we end up with (i). Is that correct and the intention? Yes. > (2) > This document already has a comment in the security section about the > potential > security impact of using this extension. I think that this document could > benefit from an Operational Considerations section to highlight that using > this > extension is likely to impact the ability of intermediate devices to identify > QUIC packets which may change how the network handles QUIC packets, either by > giving them special treatment compared to other UDP traffic, or categorizing > them and handling them the same as all other UDP traffic. Or perhaps the > security section paragraph could be expanded to cover this point (although it > isn't really security, but observed functionality). I'm happy to add a pointer to the manageability draft to that text. That covers all of that material much better than any new section I could write might. See https://github.com/quicwg/quic-bit-grease/pull/28 for the two tweaks mentioned.
