Re: [Detnet] Robert Wilton's No Objection on draft-ietf-detnet-oam-framework-10: (with COMMENT)

["Rob Wilton (rwilton)" <[e-mail]>]

Hi Greg,

Please see inline …

From: Greg Mirsky <[e-mail]>
Sent: Thursday, January 4, 2024 12:54 AM
To: Rob Wilton (rwilton) <[e-mail]>
Cc: The IESG <[e-mail]>; [e-mail]; [e-mail]; [e-mail]; [e-mail]
Subject: Re: Robert Wilton's No Objection on draft-ietf-detnet-oam-framework-10: (with COMMENT)

Hi Rob,
thank you for your kind words and helpful comments. Please find my notes below tagged GIM>>.

Regards,
Greg

On Wed, Jan 3, 2024 at 4:35 AM Robert Wilton via Datatracker <[e-mail]<mailto:[e-mail]>> wrote:
Robert Wilton has entered the following ballot position for
draft-ietf-detnet-oam-framework-10: No Objection

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COMMENT:
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Hi,

Thanks for this document, I found it easy to read and understand.

I only have some minor comments that may help improve the document:

Minor level comments:

(1) p 6, sec 3.1.  Information Collection

   Information about the state of the network can be collected using
   several mechanisms.  Some protocols, e.g., Simple Network Management
   Protocol, send queries.  Others, e.g., YANG-based data models,
   generate notifications based on the publish-subscribe method.  In
   either way, information is collected and sent using the DetNet
   Controller Plane.

A few suggestions:
1. For SNMP, perhaps "polls for updated data" rather than "send queries".
GIM>> Thank you! Accepted.
2. YANG data models don't in themselves generate notifications, but only define
notifications that could be generated when particular events occur.  But
really, it is protocols, such as YANG Push, that are used to setup
subscriptions for the data defined in the YANG data models to be published
either on a periodic basis, or when the underlying data changes.
GIM>> Thank you for the important clarification. Would the following update, that benefits from your text, makes it clearer:
OLD TEXT:
   Others, e.g., YANG-based data models,
   generate notifications based on the publish-subscribe method.
NEW TEXT:
   Other protocols, such as YANG-Push
   [RFC8641], can be used to set up subscriptions for the data defined
   in the YANG data models to be published periodically or when the
   underlying data changes.
[Rob Wilton (rwilton)]
Yes, looks good, thanks.

(2) p 10, sec 5.1.  Replication / Elimination

       Figure 1: Packet Replication: S transmits twice the same data
                         packet, to nodes A and B.

I wasn't really sure what this diagram was intending to convey (i.e., the text
only mentions S, A, and B and none of the other nodes in the diagram).  E.g.,
perhaps make is clearer that the desination is R rather than A or B?
GIM>> Would clarifying that in the text and shortening the caption be acceptable:
OLD TEXT:
   For instance, in Figure 1, the source device S is
   transmitting a packet to devices A and B.
NEW TEXT:
   For instance, in Figure 1, the source device S
   transmits a packet to devices A and B to reach the destination node
   R.
[Rob Wilton (rwilton)]
Yes, that helps clarify.

                        Figure 1: Packet Replication

(3) p 11, sec 6.  Requirements

   6.   OAM methods MAY combine in-band monitoring or measurement in the
        forward direction and out-of-bound notification in the reverse
        direction, i.e., towards the ingress MEP.

Given that this is "MAY" is doesn't appear to technically be an actual
requirement, since implementations are not required (or even recommended) to
support it.
GIM>> Would changing the title of the section to Requirements and Recommendations (although MAY is not a recommendation either) work?
[Rob Wilton (rwilton)]
I don’t think that really changes anything.  For 7/8 you could potentially combine them:

OLD:

   7.   DetNet OAM MUST support bi-directional DetNet flows.



   8.   DetNet OAM MAY support bi-directional OAM methods for bi-

        directional DetNet flows.  OAM test packets used for monitoring

        and measurements MUST be in-band in both directions.

NEW:
   7.   DetNet OAM MUST support bi-directional DetNet flows, but are
         not required to support bi-directional OAM methods for bi-
         directional DetNet flows.  OAM test packets used for monitoring
         and measurements MUST be in-band in both directions.

For 6, does it need to be stated at all, or would it be better to just remove the text?

Regards,
Rob



(4) p 11, sec 6.  Requirements

   8.   DetNet OAM MAY support bi-directional OAM methods for bi-
        directional DetNet flows.  OAM test packets used for monitoring
        and measurements MUST be in-band in both directions.

Given that this is "MAY" is doesn't appear to technically be an actual
requirement, since implementations are not required (or even recommended) to
support it.

Nit level comments:

(5) p 10, sec 6.  Requirements

   2.   It MUST be possible to initiate a DetNet OAM session from using
        any of DetNet Controller Plane solution, e.g., centralized
        controller.

Perhaps "by using any of the DetNet Controller Plane solutions"?
GIM>>Yes, the plural is the right form.

Regards,
Rob