I am an assigned INT directorate reviewer for <draft-ietf-detnet-mpls-over-ip-preof-09.txt>. These comments were written primarily for the benefit of the Internet Area Directors. Document editors and shepherd(s) should treat these comments just like they would treat comments from any other IETF contributors and resolve them along with any other Last Call comments that have been received. For more details on the INT Directorate, see https://datatracker.ietf.org/group/intdir/about/.

Based on my review, if I was on the IESG I would ballot this document as NO OBJECTION.

This document is generally well-written, and it provides a straightforward solution to the stated motivation (specifying the encoding of sequence information in DetNet IP packets). To the extent of my limited understanding of DetNet and related technologies, I've not found any issue.

The following are minor issues (typos, misspelling, minor text improvements) with the document:

I have a few comments that might help improve readability of the document.

- Introduction:

   The DetNet Working Group has defined Packet Replication (PRF), Packet
   Elimination (PEF) and Packet Ordering (POF) functions to provide
   service protection by the DetNet service sub-layer [RFC8655].  The
   PREOF service protection method relies on copies of the same packet

  I'd suggest updating the first sentence to, e.g., "...functions (correctly represented as PREOF)...", so that readers won't be puzzled about the acronym when they read the second sentence. (abstract defines the term, but I think it's better if the main text is more self-contained).

- Section 4.1, Figure 2: what "d-CW" stands for is explained in Section 4.2, but not here or before. It's more reader friendly to note it when it first occurs.

- Section 4.4: it may be more reader friendly to explain what PW stands for here:
   In the first case, the different DetNet PWs use the same UDP tunnel,

  perhaps it's obvious for readers with sufficient background, but this document generally seems to expand many acronyms, so it would be more consistent.

- Section 4.6 and Figure 5: the purpose of this section and the figure is not clear to me. Do we need this section at all?