Re: [Roll] Ralph Droms' No Objection on draft-ietf-roll-minrank-hysteresis-of-11: (with COMMENT)

["Adrian Farrel" <[e-mail]>]

Authors,

Although the Discusses are now cleared thanks to your latest revision, it would be good if you could look at the comments that Ralph has raised.

Are there changes you would like to make to address these comments? Will you spin a new revisions or can you express them in RFC Editor notes?

Thanks,
Adrian

> -----Original Message-----
> From: [e-mail] [mailto:[e-mail]] On Behalf Of Ralph
> Droms
> Sent: 08 July 2012 01:29
> To: The IESG
> Cc: roll; [e-mail]; roll-
> [e-mail]
> Subject: Ralph Droms' No Objection on draft-ietf-roll-minrank-hysteresis-of-11:
> (with COMMENT)
> 
> Ralph Droms has entered the following ballot position for
> draft-ietf-roll-minrank-hysteresis-of-11: No Objection
> 
> When responding, please keep the subject line intact and reply to all
> email addresses included in the To and CC lines. (Feel free to cut this
> introductory paragraph, however.)
> 
> 
> Please refer to http://www.ietf.org/iesg/statement/discuss-criteria.html
> for more information about IESG DISCUSS and COMMENT positions.
> 
> 
> 
> 
> ----------------------------------------------------------------------
> COMMENT:
> ----------------------------------------------------------------------
> 
> Thank you for addressing my Discuss points in the most recent
> rev of this document.  I've cleared my Discuss.
> 
> While these comments are non-blocking, they should be considered
> carefully as they are based on implementation experience with this
> draft.
> 
> 1. The second component of the path cost in section 3.1:
> 
>    2.  The value of the selected metric in the metric container in the
>        DIO sent by that neighbor.
> 
> is incompletely described.  While an implementor should realize from
> section 3.5 that the rank advertised by the neighbor is an
> approximation for ETX and should be used here, the text as written is
> incomplete.
> 
> 2. Also for completeness, the document should specify the
> representation used for ETX to be used in path cost computation; e.g.,
> as specified for the ETX sub-object in RFC 6551.
> 
> 3. Related to point 2, explanation of the relationship between the
> representation used for ETX and rank should be explained, especially
> considering what I think will be unexpected side effects of the value
> of DEFAULT_MIN_HOP_RANK_INCREASE defined to be 256 in RFC 6550
> interacting with the (presumed) default representation of ETX as
> defines in RFC 6551.
> 
> 4.  In section 3.4:
> 
>    If ETX is the selected metric, a node SHOULD NOT advertise it in a
>    metric container.
> 
> s/SHOULD NOT/MUST NOT/ (and this text is redundant relative to the
> last sentence of section 3.5).
> 
> 5. Are the parameter values in section 5 recommended only for use when
> the selected metric is ETX; seems to me MAX_LINK_METRIC, MAX_PATH_COST
> and PARENT_SWITCH_THRESHOLD depend on the selected metric and the
> recommended values wouldn't make much sense for, e.g., hop count.
> 
> These comments are purely editorial and offered to improve the clarity
> of the document.
> 
> 1. The paragraph immediately following table seems superfluous.  The
> list of metrics for which the rank is undefined is not complete (from
> RFC 6551).  The paragraph begs the question "why would the deployment
> choose a metric for which the rank is undefined?"
> 
> 2. Readability would be improved by writing the details of the
> special-case treatment of ETX (currently in section 3.5) to the point
> at which that special-case treatment modifies other behavior specified
> in the document; e.g., the second component of the path cost cited
> above.
> 
> 3. The second sentence of section 6 is pretty opaque.  Is the point
> that the "List of supported metrics" from section 18.2.3 need not be
> supported if MRHOF is used?
> 
> 4. Isn't the last paragraph of section 6.1 true for any selected metric?