[mpls] Martin Vigoureux's Yes on draft-ietf-mpls-sfc-05: (with COMMENT)

[Datatracker on behalf of Martin Vigoureux <[e-mail]>]

Martin Vigoureux has entered the following ballot position for
draft-ietf-mpls-sfc-05: Yes

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://www.ietf.org/iesg/statement/discuss-criteria.html
for more information about IESG DISCUSS and COMMENT positions.


The document, along with other ballot positions, can be found here:
https://datatracker.ietf.org/doc/draft-ietf-mpls-sfc/



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

Hello

thank you for this document.

I know I'm being too pernickety:
You say:
   o  An SFF MUST decrement the TTL by one each time it performs a
      forwarding lookup.
but in the examples you also say:
   b.  When the packet arrives at SFFa it strips any labels associated
       with the tunnel that runs from the classifier to SFFa.  SFFa
       examines the top labels and matches the SPI/SI to identify that
       the packet should be forwarded to SFa.  The packet is forwarded
       to SFa unmodified.
and
   d.  SFFa modifies the SI in the lower label stack entry (to 254) and
       uses the SPI/SI to look up the forwarding instructions.

It could look as two forwarding lookup, which, according to the requirement,
could lead to two TTL decrements. I do read in step b that the packet is
forwarded unmodified, and read in Section 6 "The TTL in SF label stack entry is
decremented once for each forwarding hop in the SFP" but still I wonder if some
clarification wouldn't be beneficial.

nits:
   TTL:  The TTL fields in the SFC Context label stack entry SF label
      stack entry SHOULD be set to 1 as stated in Section 5,
Do you mean: SFC Context label stack entry *and* SF label stack entry ?

s/document)./document./