This document has been reviewed as part of the transport area review team's ongoing effort to review key IETF documents. These comments were written primarily for the transport area directors, but are copied to the document's authors and WG to allow them to address any issues raised and also to the IETF discussion list for information. When done at the time of IETF Last Call, the authors should consider this review as part of the last-call comments they receive. Please always CC tsv-art@ietf.org if you reply to or forward this review. Summary: I think this document is almost ready for publication, but I would be grateful if the following points are clarified. 1: Is there any possibility that we will have other protocols for demultiplexing in the future? It seems that QUIC consumes most of all remaining byte ranges, which seems to affect the future extensions of the scheme. 2: "The solution discussed in this document could potentially introduce some additional security considerations beyond those detailed in [RFC7983]." -> Wouldn't it be better if we can describe a bit more about which part of the solution could have potential concern? It seems that this sentence looks less informational. 3: I probably might miss something, but I am wondering why we will publish another RFC for updating multiplexing scheme. Wouldn't it simpler to create a new doc to replace RFC7983 rather having two docs? If we will need to update the multiplexing scheme in the future, will we have 3 docs? Thanks, -- Yoshi