[PCN] tsv-dir review for draft-ietf-pcn-encoding-comparison-06

[Pasi Sarolahti <[e-mail]>]

Hello,

I've reviewed this document as part of the transport area directorate'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 for their information and to allow them to address any issues raised. The authors should consider this review together with any other last-call comments they receive. Please always CC [e-mail] if you reply to or forward this review.

Summary: This draft is ready for publication as an Informational RFC (but see the editorial suggestions below)


Detailed comments:

* Introduction, para 4: "...design and applicability of PCN-based AC and FT." -- AC and FT have not been described (this is only done later, in the next section)

* Sec. 2.2.1, para 3: "If the proportion of re-marked (ThM- and ETM-) PCN traffic is larger than a CLE-limit..." -- CLE-limit is not introduced. It would be good to shortly describe it here, even if it is specified in another PCN document.

* Sec. 3.2.2, title: "Tunneling Rules for the Handling of the DSCP" -- the wording of the title feels inconvenient. For example, would "Tunneling rules for DSCP" be any better (or not)?

* end of sec 3.2.3: "Therefore, option (1) is selected." -- selected for what?

* Sec 3.3 -- it might be useful to shortly tell why it is ok to redefine ECN bits.

* Sec. 4, para 1: "PCN semantics apply only to one or at most two specific DSCPs, and therefore ECN semantics do not apply to them" -- this sentence is a bit difficult to parse. Could it be reworded somehow? The point is to say that ECN semantics do not apply to PCN DSCPs, or what?

* Figure 7 -- Are the PCN-n and PCN-m codepoints specified somewhere? If so, add a reference.

* Sec 4.1, para 2: "The 10-codepoint is reserved for experimental purposes" -- this is not consistent with table 7, where EXP is on 01 - column.

- Pasi