A YANG Data Model for Layer 0 Types
draft-ietf-ccamp-layer0-types-09

[[ nits ]]

[ section 3 ]

* "min-slot-width-factor" and "max-slot-width-factor" could each have their
  description be simplified to refer only their own definition (as opposed
  to the shared duplicated text).

  Also, I'm not sure how to read "...of the slot width , granularity,".
  Should that just be "...of the slot width granularity,"?

* "this constraints is reported" could use a grammar fix. I'm guessing
  "this constraint is reported"?

The shepherd writeup highlights that YANGDOCTORS reviewed this twice, but the last one was five versions and almost a year ago.  Should this be refreshed?

[To the IESG:] The shepherd writeup also confirms the intended status, but doesn't answer the question as to why that's the right answer for this document.  This seems to be a common mistake.  Should the writeup change to make it clear we'd like that question answered?  Or should we just include this in the things we check during AD Evaluation?

Clearing my previous DISCUSS (about the absence of BCP 14 boilerplate) as there is no normative language in the document, there is obviously no need for the BCP 14 boilerplate...

Sorry about the fuzz... I need more coffee it seems !

Regards

-éric

Section 1.2

   YANG module ietf-layer0-types (defined in Section 3) references
   [RFC6163], [RFC7205], and [RFC7698].

RFC 7205 looks like a typo for 6205 -- I don't think that "Use Cases for
Telepresence Multistreams" is relevant for WSON.  That said, we
reference 6205 many times in the rest of the document, so (IIUC) we
don't need to mention it here in order to have a reference in the
document outside of the module itself?

Section 2

I'm not sure how appropriate RFC 6205 is as a reference for all of the
indicated terms; e.g., I don't see mention of "start", "end", "range",
or "hop" as applying to labels, there.

Section 3

     grouping l0-label-range-info {
       description
         "Information for layer 0 label range.";

nit(?): "information for" makes me expect that this will be describing
the range itself, but the contained type and priority seem to be more
metadata about the range than the range itself.  To me, writing
"Information about the layer 0 label range" would feel more natural.

     grouping flexi-grid-label-range-info {
       description
         "Info of Flexi-grid-specific label range";

nit: "Info of" seems rather colloquial; the same "Information about"
construction I suggested above seems like it would work well here, since
this is also a -label-range-info grouping.

It seems unusual to me (admittedly, not a YANG expert) that the
descriptions for min-slot-width-factor and max-slot-width-factor
separately refer to a "range" when each one only provides half of the
range.  I guess this is related to Erik's comment.

              Minimum slot width should be smaller than or equal to
              Maximum slot width. ";

Similarly, this restriction seems like one that can be expressed as a
YANG "must" directive, which it looks like Rob already noted.

Section 4

   modules.  It is critical consider how imported definitions will be
   utilized and accessible via RPC operations, as the resultant schema
   will have data nodes that can be writable, or readable, and will have

nit: "critical to consider"

Section 8.2

Don't RFCs 6163, 6205, 7698, and 8363 need to be normative since they
are used as references for YANG elements?

Hi,

Thank you for your effort on this document.  I appreciate that I have reviewed this module previously.  I have a few minor (mostly editorial) comments on the latest revision of the YANG module:

A few minor comments on the latest version of the YANG module:

Some of the descriptions have been wrapped at less than 69 characters.  Corrected examples are below.

1)
  grouping wson-label-start-end {
    description
      "The WSON label-start or label-end used to specify WSON label
       range.";

2)
          case single {
            leaf dwdm-n {
              type l0-types:dwdm-n;
              description
                "The given value 'N' is used to determine the nominal
                 central frequency.";
            }
          }

3)       
    leaf priority {
      type uint8;
      description
        "Priority in Interface Switching Capability Descriptor
         (ISCD).";

4)       
  grouping flexi-grid-label-start-end {
    description
      "The Flexi-grid label-start or label-end used to specify
       Flexi-grid label range.";

5)
      case super {
        list subcarrier-flexi-n {
          key flexi-n;
          uses flexi-grid-frequency-slot;
          description
            "List of subcarrier channels for flexi-grid super
             channel.";
        }
      }

6) 
      leaf slot-width-granularity {
        type identityref {
          base flexi-slot-width-granularity;
        }
        default flexi-swg-12p5ghz;
        description
          "Minimum space between slot widths. Default is 12.500 GHz";


The following leaf had an extra blank line before the description:
PROPOSED:

    leaf flexi-n {
      type l0-types:flexi-n;
      description
        "The given value 'N' is used to determine the nominal central
         frequency.";
    }

Please change the description to "Flexi-grid-specific label range related information", i.e.,

CURRENT:
  grouping flexi-grid-label-range-info {
    description
      "Info of Flexi-grid-specific label range";
    
PROPOSED:    
  grouping flexi-grid-label-range-info {
    description
      "Flexi-grid-specific label range related information";
    uses l0-label-range-info;

       
Nit, some of the descriptions have an extra trailing space after the full stop, plesae search/replace '. "'

For min-slot-width-factor, I would suggest removing the last sentence, and only specifying the constraint on the max-slot-width-factor, and also define a must statement as well.

CURRENT:
      leaf min-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        default 1;
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.

           Minimum slot width is calculated by:
             Minimum slot width (GHz) =
               min-slot-width-factor * slot-width-granularity.
           Minimum slot width should be smaller than or equal to
           Maximum slot width. ";
           
PROPOSED:
      leaf min-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        default 1;
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.

           Minimum slot width is calculated by:
             Minimum slot width (GHz) =
               min-slot-width-factor * slot-width-granularity.";
        reference
          "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
           Dense Wavelength Division Multiplexing (DWDM) Networks";
      }

I suggest tweaking the description and adding a must constraint to the max-slot-width-factor.  My assumption here is that a client could set the min-slot-width-factor to 2, and doesn't need to also specify max-slot-width-factor unless they want it to be greater than 2.  Coversely, they can specify both if they wish.

CURRENT:
      leaf max-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.


           Maximum slot width is calculated by:
             Maximum slot width (GHz) =
               max-slot-width-factor * slot-width-granularity
           Maximum slot width should be bigger than or equal to
           Minimum slot width. ";
        reference
          "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
           Dense Wavelength Division Multiplexing (DWDM) Networks";
      }
      
PROPOSED:
      
      leaf max-slot-width-factor {
        type uint16 {
          range "1..max";
        }
        must '. >= min-slot-width-factor' {
          error-message
            "Maximum slot width must be greater than or equal to
             minimum slot width.";
        }
        description
          "Slot width range: two multipliers of the slot width ,
           granularity, each indicating the minimal and maximal slot
           width supported by a port, respectively.

           Maximum slot width is calculated by:
             Maximum slot width (GHz) =
               max-slot-width-factor * slot-width-granularity

           If specified, maximum slot width must be greater than or
           equal to minimum slot width.";
        reference
          "RFC8363: GMPLS OSPF-TE Extensions in Support of Flexi-Grid
           Dense Wavelength Division Multiplexing (DWDM) Networks";
      }


Regards,
Rob