Subject: [RTG-DIR] statement on domain wide mpls labels

From: Loa Andersson <[email-masked]>
Date: Wed, 08 Oct 2014 15:54:43 +0200

Alvaro and John,

As you saw in my rtg-dir QA review I had a question on domain-wide
labels and whether the SID is a domain wide label or not.

Sasha pick this up and re-iterated the question, obviously having
the same problem as I have with understanding from the text whether
we see the emergence of domain wide labels or not.

Stefano responded to us that this is definitely not a domain wide
label.

I assume that you agree with Stefano. We have two issues

- a clean up of the text is need, for the time being I guess this
   is something between me and the authors (like the rest of my
   comments).

- we have drafts showing up in the mpls wg claiming that the spring
   working will are defining domain wide labels, I think this requires
   statement from the wg chairs telling everyone that the wg consensus
   is that we are not doing so. Would be extremely helpful for the mpls
   working group chairs and I guess also for you.

/Loa
-- 

Loa Andersson                        email: [email-masked]
Senior MPLS Expert                          [email-masked]
Huawei Technologies (consultant)     phone: +46 739 81 21 64

---

From: Hannes Gredler <[email-masked]>
Date: Wed, 8 Oct 2014 16:16:28 +0200

loa,

On Wed, Oct 08, 2014 at 03:54:43PM +0200, Loa Andersson wrote:
| As you saw in my rtg-dir QA review I had a question on domain-wide
| labels and whether the SID is a domain wide label or not.
| 
| Sasha pick this up and re-iterated the question, obviously having
| the same problem as I have with understanding from the text whether
| we see the emergence of domain wide labels or not.
|
| Stefano responded to us that this is definitely not a domain wide
| label.

it's certainly not a re-emergence of domain-wide labels.
early IS-IS interop testing between ALU, CSCO and JNPR also
indicates that what has been implemented is a domain-wide index
imposed on local-labels which is in line with rfc3031.

i see early slidedecks/descriptions (which are still floating around)
still have that idea of "domain-wide" labels - appreciate if
any traces of this can get removed as it creates constant
confusion.

let me add also add a personal note that adding "domain-wide" labels
(more than 15 years after inception of MPLS) does practically not work.
commercial label-allocation software often has fixed per-application
label-space partititions, there is hardware/platform dependencies
(e.g. forwarding hardware that only have got space for 16-bit tables entries)
and, ohh well, upstream label allocation). trying to punch a domain-wide
common "hole" in the label-allocation of the deployed vendors,
is often not possible.

/hannes
 
| I assume that you agree with Stefano. We have two issues
| 
| - a clean up of the text is need, for the time being I guess this
|   is something between me and the authors (like the rest of my
|   comments).
| 
| - we have drafts showing up in the mpls wg claiming that the spring
|   working will are defining domain wide labels, I think this requires
|   statement from the wg chairs telling everyone that the wg consensus
|   is that we are not doing so. Would be extremely helpful for the mpls
|   working group chairs and I guess also for you.

---

From: "Alvaro Retana (aretana)" <[email-masked]>
Date: Wed, 8 Oct 2014 18:34:17 +0000

On 10/8/14 9:54 AM, "Loa Andersson" <[email-masked]> wrote:

Loa:

Hi!

>   is something between me and the authors (like the rest of my

AFAIK, Stefano is cleaning up the text as discussed.

>   working group chairs and I guess also for you.

Well..all we have right now is a call for adoption of the document (which
ends today..but will be extended until the IPR claims have been submitted
and the WG has time to consider).  IOW, even if the document is adopted, I
don't think we can claim WG consensus yet.

Having said that, the work in progress
(draft-filsfils-spring-segment-routing-mpls, with the cleaned text of
course) should be reference enough to satisfy anyone making such claims.

My 2c.

Alvaro.