Last Call Review of draft-ietf-pim-reserved-bits-03
review-ietf-pim-reserved-bits-03-genart-lc-yee-2019-09-03-00

Request Review of draft-ietf-pim-reserved-bits
Requested rev. no specific revision (document currently at 04)
Type Last Call Review
Team General Area Review Team (Gen-ART) (genart)
Deadline 2019-09-03
Requested 2019-08-20
Authors Stig Venaas, Alvaro Retana
Draft last updated 2019-09-03
Completed reviews Secdir Last Call review of -03 by Dan Harkins (diff)
Genart Last Call review of -03 by Peter Yee (diff)
Opsdir Last Call review of -03 by Susan Hares (diff)
Assignment Reviewer Peter Yee 
State Completed
Review review-ietf-pim-reserved-bits-03-genart-lc-yee-2019-09-03
Posted at https://mailarchive.ietf.org/arch/msg/gen-art/8vKErKTE77S_W7AWafMgUhmTVVw
Reviewed rev. 03 (document currently at 04)
Review result Ready with Issues
Review completed: 2019-09-03

Review
review-ietf-pim-reserved-bits-03-genart-lc-yee-2019-09-03

I am the assigned Gen-ART reviewer for this draft. The General Area
Review Team (Gen-ART) reviews all IETF documents being processed
by the IESG for the IETF Chair.  Please treat these comments just
like any other last call comments.

For more information, please see the FAQ at

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Document: draft-ietf-pim-reserved-bits-03
Reviewer: Peter Yee
Review Date: 2019-09-03
IETF LC End Date: 2019-09-03
IESG Telechat date: Not scheduled for a telechat

Summary:  This document clarifies use of the PIM message header Reserved bits and adds subtypes in order to extend the type space to allow for future usage.  The expansion seems straightforward and reasonable.  [Ready with Issues.]

Major issues: None

Minor issues:

Page 6, Table 1: I'm not a fan of this table format.  It overloads the Name column header to describe both the Type and the Flag Bits.  Perhaps something that looks like (use a fixed-width font to view this properly):

    Type       Flag Bits   Name    Flag Bits Desc.        Reference
   ---------------------------------------------------------------------
     0                     Hello                       [RFC3973][RFC7761]
                 0-7               Reserved
...
    10                     DF Election                 [RFC5015]
                 0-3               Reserved
                 4-7               Subtype

It's a suggestion.  I just don't find the overloaded column header and repeated data particularly appealing.  It took me a few seconds to figure out what was being done here.  As it is, Name isn't a terribly good way of describing the meaning of the Flag Bits.  Just a suggestion.

Nits/editorial comments:

General: 

On all pages except the first, in the page header: change "Extention" to "Extension".

Page 1, Abstract, 2nd and 3rd paragraphs: change all uses of RFCxxxx to RFC xxxx.  The space-less form is only used for references within square brackets.

Specific:

Page 1, Abstract, 1st paragraph, 3rd sentence: change "per message" to "per-message".

Page 3, Section 4, 1st paragraph, 3rd sentence: delete the comma.

Page 3, Section 4, 2nd paragraph, 1st sentence: append a comma after "Bits".  Change "well defined" to "well-defined".

Page 4, Section 5, 1st sentence: change "pim" to "PIM".

Page 5, Figure 3 caption: You've used "sub-type", "SubType", "Subtype" (from the revised IANA registry in Table 1) and here "Sub-Types".  I'd suggest choosing one form and using it more consistently.  Given the spacing requirements of the diagram, a hyphenated form would probably not be the optimal choice.