Subject: [Bier] Éric Vyncke's No Objection on draft-ietf-bier-te-arch-10: (with COMMENT)

From: Éric Vyncke via Datatracker <[email-masked]>
Date: Thu, 26 Aug 2021 05:04:12 -0700

Éric Vyncke has entered the following ballot position for
draft-ietf-bier-te-arch-10: No Objection

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COMMENT:
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Thank you for the work put into this document. As I am back from vacations, I
am afraid that I had only browsed quickly through this dense document, please
accept my apologies for that. Please also note that I am not familiar with BIER.

Please find below some non-blocking COMMENT points (but replies would be
appreciated even if only for my own education), and some nits.

I hope that this helps to improve the document,

Regards,

-éric

== COMMENTS ==

-- Abstract --
I find the statement "Co-existence of BIER and BIER-TE forwarding in the same
domain is possible, for example by using separate BIER sub-domains (SDs)" quite
an oxymoron as co-existence in a single domain requires splitting the domain
into sub-domains. Suggest to rather mention sharing the BIFT-id address space
among BIER and BIER-TE.

In the statement "BIER-TE can also be a good fit to support multicast path
steering in Segment Routing (SR) networks" s/can also be a good fit/is shown to
be a good fit/ ? Even if section 6 is really light on the topic.

-- Section 1 --
Please expand "BIFT" and "BFR" at first use as other BIER terms are expanded.

-- Section 2.4 --
The blanket/broad statement that "Forwarding of BIER-TE is designed to easily
build/program common forwarding hardware with BIER." is it applicable to all
hardware handling BIER ? Or is it vendor specific ?

-- Section 3.2.1 --
As BIER-TE is basically centralized in a control, "such YANG/Netconf/RestConf"
is a little hand waving. Does the BIER WG have already started work on this
control protocol ?

-- Section 4.2.3 --
What is the "entropy parameter" ? where is it defined ? (to repeat myself, I am
not a BIER expert) if the entropy is part of the BIER header then strong
suggestion to s/entropy parameter/value of the entropy field of the BIER
header/.

-- Section 4.3 --
Do the authors have an idea on how to share the BIFT-id address space among
BIER (which is decentralized AFAIK) and BIER-TE (which is centralized) without
overlapping and keeping the separation during all operations (including when
nodes/links appear/disappear) ?

-- Section 6 --
While discussing about SR, did the WG think about using RFC 8986 network
programming to achieve the same results as BIER-TE ?

Unsure whether the note about "BIER itself" brings any value in this BIER-TE
document.

Unsure what the last § has to do with segment routing.

To be honest, this section is really light and the document would gain by
removing it.

== NITS ==

Please use the all uppercase "YANG" rather than "Yang" as it is an acronym.

-- Section 2.3 --
s/that is forwarding plane is a simple extension/that its forwarding plane is a
simple extension/ ?