Last Call Review of draft-ietf-softwire-map-10
review-ietf-softwire-map-10-opsdir-lc-brownlee-2014-10-12-00

Hi all:



I have reviewed this document as part of the Operational directorate's 


ongoing effort to review all IETF documents being processed by the 


IESG.  These comments were written primarily for the benefit of the 


operational area directors.  Document editors and WG chairs should treat 


these comments just like any other last call comments.






This draft specifies the DHCPv6 options needed to configure Softwire46 


Customer Edge devices so as to provide IPv4 connectivity across an IPv6 


network.  The options are grouped into three 'containers,' one for each 


type of Softwire46 mapping; each container may have several sub-options 


within it.  The draft describes the sub-options first, then the 


containers and a table of which sub-options are mandatory, optional or 


not allowed in each.




Overall I believe this document is ready to publish.



From the 'Operations' point of view, it's clear that this technology is 


somewhat complicated to deploy - its various parts all need to work 


together properly.  Providers using it need to be sure that their 


boundary routers and their customers edge devices will interwork 


properly.  That said, having DHCP as a tool to help with configuring 


edge devices is well worth while.






When reading it, I found that I had to read it right through before I 


understood the way sub-options are to be grouped - that became clear in 


section 6, which presents the table showing what's allowed where.  I 


suggest a sentence at the end of section 3 (Softwire46 Overview) as a 


forward reference to section 6 would be helpful.






In section 4.1, I found the explanation of the F flag confusing.  If 


it's set the rule "is to be used as" a forwading rule (FMR), if not set 


"this rule is a basic rule (BMR).  But the last sentence in the 


paragraph says it may be both.  Maybe the F flag says that although the 


rule is a BMR, it may also be used as an FMR?




Last, one (yes, only one) typo:
Last paragraph of section 8: s/Note that system implementing/
                               Note that a system implementing/

Cheers, Nevil

--
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 Nevil Brownlee                          Computer Science Department
 Phone: +64 9 373 7599 x88941             The University of Auckland
 FAX: +64 9 373 7453   Private Bag 92019, Auckland 1142, New Zealand