Last Call Review of draft-ietf-v6ops-ipv6-roaming-analysis-05
review-ietf-v6ops-ipv6-roaming-analysis-05-genart-lc-yee-2014-10-02-00

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Gen-ART, please see the FAQ at
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Please resolve these comments along with any other Last Call comments you
may receive.

Document: draft-ietf-v6ops-ipv6-roaming-analysis-05
Reviewer: Peter Yee
Review Date: September-30-2014
IETF LC End Date: September-29-2014
IESG Telechat date: TBD

Apologies for the late review -- I've been on vacation and didn't quite get
everything keyed in before the deadline.  I hope you still find the review
useful.

Summary: This draft is ready with issues for publication as an Informational
RFC. [Ready with issues]

This draft discusses some of the issues that may occur when a mobile device
roams on a visited network and attempts to use IPv6.  The technical meat of
the draft is fine, but the language usage makes it difficult to read through
without extra effort and reflection.  I'm not a 3GPP expert by any stretch
of the imagination, so I can't tell if the analysis made is sufficiently
comprehensive, but it appears to cover all of the IPv4/IPv6 combinations and
home/local breakout uses cases.

Minor issues: 

General: 

There are a lot of definite (the) and indefinite articles (a/an) missing in
the draft.  This makes it really difficult to read and interpret what is
meant.  In some cases, the plural form would also make sense, so it's hard
to know how to interpret the sentence.  I hate to say it, but please look
carefully at pretty much any acronym/initialism and the common nouns.  Make
a determination if an article is appropriate.  I started to mark these items
in the document while doing my review but became bogged down by the sheer
number of missing and in a few cases superfluous articles.  I do understand
that English may not be a primary language for several of the authors and
appreciate your indulgence in trying to make the document more readable and
therefore more useful.


Nits:

General: 

Ensure that the abbreviations i.e and e.g. are followed by a comma
consistently.

Separate references from the preceding text with a space, again for
readability.

I'll leave the Oxford/Harvard/serial comma alone for this review -- the
first general nit will take enough time to straighten out!

Specific: 

Page 3, 4th bullet item, 2nd sentence: omit the commas.

Page 4, Section 2.1.1, 2nd paragraph, 1st sentence: change "is" to "are".

Page 6, 1st paragraph: replace the space after "breakout" with a hyphen.

Page 6, 2nd bullet item: delete "a".

Page 8, 1st partial paragraph, 3rd full sentence: append a comma after
"updated".  Delete the "(" before "Section 6".

Page 9, 1st bullet item, 2nd sentence: delete the 2nd appearance of "only".

Page 9, 2nd bullet item, 3rd sentence: "lose" doesn't seem to be the right
word here.  I would think that the subscriber simply would not be able to
obtain an IPv6 connection.

Page 10, 1st partial paragraph: append "an error" after "not".

Page 10, 1st paragraph after bullet items, 1st sentence: change "support" to
"supports".

Page 10, Section 4.2, 2nd paragraph, 2nd sentence: I don't think the word
risky is what you mean.  More like guaranteed, right?

Page 10, Section 4.2, 2nd paragraph, 4th sentence: replace the space after
"roaming" with a hyphen.

Page 11, Section 4.3, 2nd sentence: change "to support" to "of supporting".
Make the immediately following "type" plural.

Page 11, Section 4.4, 2nd paragraph, 1st sentence: delete the first "the".
Replace the second "the" with "this".

Page 11, Section 4.4, 2nd paragraph, last sentence: change "an" to "a".

Page 11, Section 5.1, 1st paragraph, last sentence: insert "to" before
"failed".  Change "failed" to "fail".  And isn't the failure more than
likely, it is essentially guaranteed?

Page 12, Section 5.2, 1st paragraph, 2nd sentence: append "used" after
"likely".

Page 12, Section 5.2, 3rd paragraph, 1st sentence: change "to" to "on".

Page 12, Section 5.2, 4th paragraph, 1st sentence: delete "the" before
"local".

Page 13, 1st paragraph after Scenario 1, 1st sentence: replace "is" with
"are".

Page 14, Section 7, 1st paragraph, 2nd sentence: change "testified" to
"illustrated".  Change "issues" to "problems".  Change "happened" to
"happen".

Page 14, Section 7, 2nd paragraph, 1st sentence: change "stage of the
network attachment" to "network attachment stage".

Page 14, Section 7, 2nd paragraph, 2nd sentence: change "early release" to
"earlier releases".

Page 14, Section 7, 2nd paragraph, 3rd sentence: change "Such" to "That".
Change "didn't" to "isn't".  Change "support" to "supported".

Page 14, Section 7, 2nd paragraph, 4th sentence: I'm simply having troubles
parsing this sentence.  Please rewrite for clarity.

Page 14, Section 7, 2nd paragraph, 5th sentence: should "SSGN" really be
"SGSN"?  If not, add a definition for "SSGN" in Section 1.1.

Page 14, Section 7, 3rd paragraph, 1st sentence: change "stage of the
PDP/PDN creation" to "PDP/PDN creation stage".  Change "type" to "types".

Page 14, Section 7, 3rd paragraph, 3rd sentence: append "that" after
"desirable".

Page 14, Section 7, 3rd paragraph, 4th sentence: append "support of" after
"For".  Change "the DAF is suggested to be set" to "it is suggested to set
the DAF".

Page 15, 1st full paragraph, 1st sentence: change "stage of service
requests" to "service requests stage".  Delete "are".

Page 15, 1st full paragraph, 3rd sentence: change "to use" to "using".
Append "mode" after "routed".  Change "the" to "these".  Change "risks" to
"problems".

Page 15, 2nd bullet item, 2nd sentence: change "an" to "a" on the assumption
that "AAA" is typically pronounced "Triple A".  Change "Radius"  to
"RADIUS".

Page 15, Section 9: change "it" to "the reader".