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

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

Hi Frank,

Please see comments inline.

> -----Original Message-----
> From: Frank Brockners (fbrockne) <[e-mail]>
> Sent: 04 May 2023 21:21
> To: Rob Wilton (rwilton) <[e-mail]>; The IESG <[e-mail]>
> Cc: [e-mail]; [e-mail]; [e-mail];
> [e-mail]
> Subject: RE: Robert Wilton's Discuss on draft-ietf-sfc-ioam-nsh-11: (with
> DISCUSS and COMMENT)
> 
> Hi Rob,
> 
> Thanks a lot for your review. We've just posted an updated revision (12):
> https://www.ietf.org/archive/id/draft-ietf-sfc-ioam-nsh-12.txt
> 
> Please see inline below:
> 
> > -----Original Message-----
> > From: Robert Wilton via Datatracker <[e-mail]>
> > Sent: Tuesday, 2 May 2023 14:53
> > To: The IESG <[e-mail]>
> > Cc: [e-mail]; [e-mail]; [e-mail];
> > [e-mail]; [e-mail]
> > Subject: Robert Wilton's Discuss on draft-ietf-sfc-ioam-nsh-11: (with
> > DISCUSS and COMMENT)
> >
> > Robert Wilton has entered the following ballot position for
> > draft-ietf-sfc-ioam-nsh-11: Discuss
> >
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> >
> >
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> > The document, along with other ballot positions, can be found here:
> > https://datatracker.ietf.org/doc/draft-ietf-sfc-ioam-nsh/
> >
> >
> >
> > ----------------------------------------------------------------------
> > DISCUSS:
> > ----------------------------------------------------------------------
> >
> > Hi,
> >
> > Thanks for this document.
> >
> > A couple of discuss points that I raised only because I find the spec to be
> > unclear which should be be easy to clarify:
> >
> > (1) p 2, sec 3.  IOAM encapsulation with NSH
> >
> >                                                        The operator MUST
> >    ensure that all nodes along the service path support IOAM.
> >
> > Is it actually 'all nodes along the service path' or "SFC aware nodes along
> > the
> > service path" that MUST support IOAM?
> 
> ...FB: Thanks. The sentence has been updated to read:
> 
> The operator MUST ensure that SFC-aware
>    nodes along the Service Function Path support IOAM, otherwise packets
>    might be dropped (see Section 3 further below, as well as [RFC8300]
>    Section 2.2).
[Rob Wilton (rwilton)] 
Looks good.  Thanks.

> 
> >
> > (2) p 3, sec 3.  IOAM encapsulation with NSH
> >
> >       IOAM HDR Len:  8 bit Length field contains the length of the IOAM
> >          header in 4-octet units.
> >
> > Does this mean quantized to 4 byte units, or that the actual length in bytes
> > is
> > 4 * "Hdr Len" field?
> 
> ...FB: John had a related comment on the length field. The updated version
> now reads:
> 
>       IOAM HDR Len:  8-bit field that contains the length of the IOAM
>          header in multiples of 4-octets, including the "IOAM-Type" and
>          "IOAM HDR Len" fields.
[Rob Wilton (rwilton)] 

So, just to check that I definitely understand.  If the hdr len field = 3, then that means that the actual length is 12 octets (3 x 4)?  If so, that is fine for me to clear the discuss.  If not, then the text isn't clear, at least to me :-)

Regards,
Rob