Re: [sfc] WG Last Call continuing on draft-ietf-sfc-nsh-tlv

Hi,

I support publication of this draft. I have a few further suggestions below
but support publication whether or not these suggestions are accepted.

Thanks,
Donald

Title
   The title is currently as follows:

Network Service Header Metadata Type 2 Variable-Length Context Headers

   This sounds to me like the title of a general document about this type of
   Metadta Contest Headers. Also, I'm notd sure it needs to say
"Varible-Length
   in the title as that is implied by the "Type 2" and covered in the body
of
   the draft. I suggest the title be changed to something like the
following:

Specifiction of Several Network Service Header (NSH) Metadata Type 2
Context Headers

Abstract
   As far as I know, square bracketed references are not allowed in the
Abstract:
OLD
   [RFC8300] to steer and provide context Metadata (MD) with each
NEW
   (RFC 8300) to steer and provide context Metadata (MD) with each

Section 4.1
   Looking at the list of types of Forwarding Contexts, I think this should
also cover "double tagging", that is, the ways people use two successive
VLAN tags, such as an S-VLAN followed by a C-VLAN. This can reault in 24
bits of Forwarding Context by combining the two VLAN IDs. There is a Type
(0x2) for a 24-bit Forwarding Context but it is for a virtual network
identifier (VNI) which seems to me like a different thing. So I would
recommend adding another type for 24-bits of double tagging as a forwarding
context. (Alternatively this could perhaps be included with the existing
24-bit Forwarding Context but the description shoild be extgended.) Perhaps
a new type with a description something like
   - 24 bits double tagging. For example a service VLAN tag followed by a
customer VLAN tag [802.1Q]. The two VLAN IDs are concatenated and appear in
the same order that they appeared in the payuload.

Sections 4.1 and 4.2
   This is just a comment, but the VNI, which is listed in Section 4.1, is
frequently thought of and referred to as a "tenant ID", but the section for
that is 4.2. I'm not sure of the best way of resolving this,

===============================
 Donald E. Eastlake 3rd   +1-508-333-2270 (cell)
 2386 Panoramic Circle, Apopka, FL 32703 USA
 d3e3e3@gmail.com

On Thu, Apr 15, 2021 at 9:32 AM Joel M. Halpern <jmh@joelhalpern.com> wrote:

> This last call was issued on teh 1st of April:
> https://mailarchive.ietf.org/arch/msg/sfc/vE4fhTlIp5uCcZpC9kKK46Kba8U/
>
> We have seen 1 response on the list.
> Folks, this was considered an important part of the SFC work.  We can
> not hand it to our AD with 1 message of support.  Even though there
> appears to be no disagreement.
>
> Please speak up.  The chairs will let this run another week.
>
> Yours,
> Joel
>
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