[sfc] Éric Vyncke's Discuss on draft-ietf-sfc-ioam-nsh-11: (with DISCUSS and COMMENT)

[Éric Vyncke via Datatracker <[e-mail]>]

Éric Vyncke has entered the following ballot position for
draft-ietf-sfc-ioam-nsh-11: Discuss

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DISCUSS:
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Thank you for the work put into this document.

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

Special thanks to Greg Mirsky for the shepherd's detailed write-up including
the WG consensus ***and*** the justification of the intended status.

I hope that this review helps to improve the document,

Regards,

-éric

# DISCUSS (blocking)

As noted in https://www.ietf.org/blog/handling-iesg-ballot-positions/, a
DISCUSS ballot is just a request to have a discussion on the following topics:

## Section 3

This is probably due to my lack of knowledge about NSH... So, a simple
discussion over email will probably be enough to clear my DISCUSS points.

RFC 9197 has an incremental tracing (section 4.4.1), how does it impact the
length of the IOAM header in this case? Assuming that this header size is
increased, I suggest to add some text about increasing the length field of IOAM
header.

`When a packet with IOAM is received at an NSH based forwarding node such as an
Service Function Forwarder (SFF) that does not understand IOAM header, it
SHOULD drop the packet.` is actually a copy of RFC 8300 ```   Packets with Next
Protocol values not supported SHOULD be silently dropped
      by default, although an implementation MAY provide a configuration
      parameter to forward them. ```
and not a new behaviour. So, let's rather be clear and use a structure like
"Per section 2.2 of RFC 8300, ..." followed by the RFC 8300 text. While very
similar to Jim Guichard's DISCUSS point, it is related to another part of the
document.


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COMMENT:
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# COMMENTS (non-blocking)

## Section 1

Please expand SFF at first use.

## Section 3

Please expand ESP (is it IPsec ESP ?) in the packet format.

Should there be text about the absence of padding in the "IOAM Option and
Optional Data Space" field (assuming that all IOAM options are always in 32-bit
units)?

## Section 4

`IANA is requested to allocate protocol numbers for the following "NSH Next
Protocol" related to IOAM` is underspecified. If it is about
https://www.iana.org/assignments/nsh/nsh.xhtml#next-protocol, then let's be
clear.

Note: I intended to DISCUSS this point, but as Jim is already holding a DISCUSS
on the same point, I will let him to be the owner.

# NITS (non-blocking / cosmetic)

A couple of missing hypens in "open source" or "8 bit field".