Considerations for Assigning a New Recommended Differentiated Services Code Point (DSCP)
draft-ietf-tsvwg-dscp-considerations-13

# John Scudder, RTG AD, comments for draft-ietf-tsvwg-dscp-considerations-12
CC @jgscudder

## COMMENTS

Thanks for this interesting document, I enjoyed reading it. I have a number of comments that I hope will be helpful; I'm somewhat concerned they may come off as nitpicking but in some of the cases I really did find that (for example) lack of a comma seriously impeded my ability to understand the material. 

### Section 1, Expand "BA"

Please expand "BA" on first use, presumably you'd do this by putting "(BA)" next to your first and only use of "Behavior Aggregates".

### Section 2, The term 'remarking'

You might mention in your Terminology section that you use the term "remarking" in a nonstandard (with respect to the normal rules of English orthography) way, pronounced and construed as "re-marking". Then again, maybe the entire document set around DSCP already has this quirk so the ship has sailed? Your call, but you do say in Section 6 that your intended audience is the entire IETF and IESG, so it might be worth erring on the side of generosity here.

### Section 3.1, Unclear clause

The parenthetical

	where 'x' refers to either a bit position with value '0' or '1'
	
Is unclear, probably what you mean is

	where 'x' refers to a bit position with value either '0' or '1'
	
### Section 3.1, Pool 3

I found the discussion of 0x01, 0x03, 0x05, 0x07 under the heading of Pool 3 to be confusing, considering that we are told Pool 3 has format 0bxxx01, and so 0x03 and 0x07 are by definition not part of it. Would it make sense to end the description of Pool 3 right after "... if Pool 1 is ever exhausted" and make the remaining text a standalone paragraph and not part of the Pool 1/2/3 hanging list?

### Section 3.2, For want of a comma, the point was lost

I wasn't able to unambiguously construe

```
Similarly, another study found many routers remark all traffic except those packets with a DSCP that sets the higher order bits to 0b11 (see Section 4 of this document).
```

until I finally found the answer in the final paragraph of Section 4.2.1. So, at the very least you might update your reference to point the bamboozled reader specifically to that paragraph or at least subsection. I would also suggest at minimum adding a comma between "traffic" and "except", but really why not just rewrite it in a way that's a bit more direct?

### Section 4.2.1, Gnomic entries in Table showing 0b000xxx DSCPs

I was expecting that some later text would help me understand what "ToS Prec B1. of AF11..41", "EXP/LU", "ToS Prec B1 of AF13..EF" and "Exp/LU" mean, but none ever came. I surmise that the "ToS Prec" business means "these are assigned things that ToS-bleach down to the same thing", but really the work to figure that out was greater than the work to just read the preceding "Table of DSCP values" and come to the conclusion myself. And neither "EXP/LU" nor "Exp/LU" (why the different capitalizations?) are ever explained.

It seems to me that this table is too pithy to be of use to the casual reader such as myself, and likely too obvious to be of use to the expert reader.

### Section 4.2.1, Is LE 1, or 4?

You write "The Lower-Effort Per-Hop Behavior PHB (LE) uses a DSCP of 4". But elsewhere (the "Table of DSCP values", other tables, Section 6.2.1) you tell me LE is DSCP 1. 

### Section 5.1.1 Including? Included?

"IEEE 802.1Q specified a 3-bit Priority Code Point (PCP) field including in a tag that allows Ethernet frames to be marked as one of eight priority values [IEEE-802-1Q]."

I don't know from 802.1Q, so I can't work out if there's a comma missing before "including", or if "including" should be "included". (Or something else I haven't contemplated.)

## NITS

"as well unassigned DSCPs" -> "as well as unassigned DSCPs" (insert 'as')

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. 

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments

# GEN AD review of draft-ietf-tsvwg-dscp-considerations-12

CC @larseggert

## Comments

### Missing references

No reference entries found for these items, which were mentioned in the text:
`[RFC5415]`.

## Nits

All comments below are about very minor potential issues that you may choose to
address in some way - or ignore - as you see fit. Some were flagged by
automated tools (via https://github.com/larseggert/ietf-reviewtool), so there
will likely be some false positives. There is no need to let me know what you
did with these suggestions.

### Outdated references

Reference `[RFC1349]` to `RFC1349`, which was obsoleted by `RFC2474` (this may
be on purpose).

Reference `[RFC3662]` to `RFC3662`, which was obsoleted by `RFC8622` (this may
be on purpose).

### Grammar/style

#### Section 4, paragraph 2
```
e DSCP field to any value different than 0b000 (replace the 3 bits of the fo
                                    ^^^^
```
Did you mean "different from"? "Different than" is often considered colloquial
style. [DIFFERENT_THAN] (Also elsewhere.)

#### Section 4.2.2, paragraph 5
```
stems and subnetworks can, and do, utilise the DiffServ field in an IP packet
                                   ^^^^^^^
```
Do not mix variants of the same word ("utilise" and "utilize") within a single
text. [EN_WORD_COHERENCY] (Also elsewhere.)

#### Section 4.3, paragraph 2
```
E Ethernet 802.1Q header, the 3-bit WiFi UP field or the 3-bit Traffic Class
                                    ^^^^
```
Did you mean "Wi-Fi"? (This is the officially approved term by the Wi-Fi
Alliance.). [WIFI] (Also elsewhere.)

## Notes

This review is in the ["IETF Comments" Markdown format][ICMF], You can use the
[`ietf-comments` tool][ICT] to automatically convert this review into
individual GitHub issues. Review generated by the [`ietf-reviewtool`][IRT].

[ICMF]: https://github.com/mnot/ietf-comments/blob/main/format.md
[ICT]: https://github.com/mnot/ietf-comments
[IRT]: https://github.com/larseggert/ietf-reviewtool