Re: [Bier] Robert Wilton's No Objection on draft-ietf-bier-bar-ipa-12: (with COMMENT)

["Jeffrey (Zhaohui) Zhang" <[e-mail]>]

Hi Rob,

Sorry for the late response. I took some time off work and am catching up on delayed work.

Please see zzh> below.


Juniper Business Use Only

-----Original Message-----
From: Robert Wilton via Datatracker <[e-mail]> 
Sent: Tuesday, April 19, 2022 7:27 AM
To: The IESG <[e-mail]>
Cc: [e-mail]; [e-mail]; [e-mail]; Greg Mirsky <[e-mail]>; [e-mail]; [e-mail]
Subject: Robert Wilton's No Objection on draft-ietf-bier-bar-ipa-12: (with COMMENT)

[External Email. Be cautious of content]


Robert Wilton has entered the following ballot position for
draft-ietf-bier-bar-ipa-12: 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 https://urldefense.com/v3/__https://www.ietf.org/about/groups/iesg/statements/handling-ballot-positions/__;!!NEt6yMaO-gk!SFxqK7NzdwzMDkjyRUZwmQMJmCf2gkwiZofHioZ4I2KHOk_qeEl2KAaNqe4TXl_8$
for more information about how to handle DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://urldefense.com/v3/__https://datatracker.ietf.org/doc/draft-ietf-bier-bar-ipa/__;!!NEt6yMaO-gk!SFxqK7NzdwzMDkjyRUZwmQMJmCf2gkwiZofHioZ4I2KHOk_qeEl2KAaNqY7YWk4T$



----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------

Hi,

Thanks for this.

A few minor comments:

(1)
   This document specifies general rules for the interaction between the
   BIER Algorithm (BAR) and the IGP Algorithm (IPA) used for underlay
   path calculation when other BAR and/or IPA values are used.

I wondered whether it would helpful to clarify that "other" means "non zero", e.g., "when other (i.e., non zero) BAR and/or IPA values are used"

Zzh> Done. Will post the revision once comments from others are also addressed.

(2)
   When a BAR value is defined, the corresponding BA and BC semantics
   SHOULD be specified.  For an IGP Algorithm to be used as a BIER IPA,
   its RA and RC semantics SHOULD be specified.

Under what conditions can these SHOULDs be violated, or to state it another way, why are they not MUSTs?

Zzh> They are not MUSTs to allow some flexibility in the specification of BAR/IPA. If one is not specified, then it is interpreted as NULL.

(3) I note that this document doesn't have, or reference, any YANG, but presumably these two fields are covered by igp-algorithm and bier-algorithm in draft-ietf-bier-bier-yang-07?  Not this document, but it would be useful if those fields included this RFC-to-be in a reference statement for those two fields, perhaps with slightly enhanced descriptions to give some indication of how the fields work together.  You might also consider including an informational reference to where the YANG management interface of these two fields is defined, but I'll leave that to the authors discretion.

Zzh> draft-ietf-bier-bier-yang does have BAR/IPA. Since this document focuses on how BAR/IPA interact not on how they're configured/monitored, I'm inclined not to mention YANG here. I am copying the main author of the YANG document so that they can update the descriptions to be consistent.

module: ietf-bier
  augment /rt:routing:
    +--rw bier
        ...
       |  +--rw igp-algorithm?            uint8
       |  +--rw bier-algorithm?           uint8

Zzh> Thanks!
Zzh> Jeffrey

Regards,
Rob