In addition, I have a few minor comments on rev -04 below:
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Abstract:
- I found the sentence that starts below to be a little hard to
read, rephrasing would be helpful:
"The new rules propagate the ECN field whether..."
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Abstract:
- There seems some recommendations buried in section 7, if these are
useful they may benefit from a mention in the abstract, such as:
"RFC 4774 permits the Diffserv codepoint (DSCP) [RFC2474] to
'switch in' alternative behaviours for marking the ECN field and
requires new methods to consider the implications of tunnel
encapsulated packets. Section 7 of this document extends the
considerations in section 5.4 of RFC 4774."
<see comments email for discussion on Section 7>
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Section 3:
- Typo, :
"inAppendix A"
^
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Section 4:
NiT:
"If absolutely necessary..."
^^^^^^^^^^
- Perhaps it is strong enough to say "necessary"? or to move the NOT
RECOMMENDED to the start of the paragraph to emphasise this.
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Section 5.1:
- This section makes a claim that some codepoint..
"has never been used on the Internet"
- Rather than face a pedantic correction with a corner case, it may
be safer just to say "is not known to have been used"...
- The same comment applies to 5.2.
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Section 5.1:
"However, this is such a remote possibility that in general.. are
NOT REQUIRED to implement."
- The in "in general" part worries me. I think this should be
expressed more clearly, since it contains some RFC 2119 keywords.
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Section 5.3.2:
- This section reads better, but still repeats a little the covert
channel theme.
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Section 7:
- separate email.
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Section 10:
- Para starting:
"The new rules...
- I think the last sentence would read better without a "But" at the start.
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Section 12:
- This section could be removed as we move to a WGLC, or marked for
later RFC-Ed removal.
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Appendix B.1:
- Para starting:
"ECN at the IP layer..."
This para finishes with:
"Therefore the goals of IPsec and ECN are incompatible."
- I don't mind if this stays as it is written, but it does sound a
kind of philosophical view, and seems odd to me.
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Appendix D:
- I wonder if thus Appendix could be more concise? (e.g. it does
repeat the covert channel case). Given this is now standards-action
can we compact some of this?
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Appendix E:
- This appendix was usefult to dervive the Spec. It now appears to
repeat what is now said earlier, and I suspect much of this text is
not needed here and would already be covered in
[I-D.ietf-pcn-marking-behaviour] - which I now think is also
scheduled for publication by PCN.
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