Re: [Idr] Part 2 of CAR/CT Adoption call (7/6 to 7/20) - Adoption of draft-dskc-bess-bgp-car-05.txt and draft-kaliraj-idr-bgp-classful-transport-planes-17.txt

["Zafar Ali (zali)" <[e-mail]>]

Hi Sue and the WG,
For the technical reasons outlined in the following:
I support adoption of the BGP CAR Draft
I oppose adoption of the CT draft
Technical Reasons:

·         A BGP transport routing solution should maintain the simplicity of BGP IP and BGP-LU. Use of VPN RDs, import/export are overkill for transport nodes and tax for the BGP control plane. BGP-CAR is identical to the BGP-LU model, extended by color.

·         BGP-CAR seamlessly works with the SR-TE architecture using Color Extended-Community in service routes and Color in the transport, thus simplifying networks that deploy both BGP and SR-TE and require co-existence and interworking. BGP-CT unnecessarily introduces different mechanisms like mapping communities, creating additional operational overhead and interop issues.

·         Supporting signaling of different encapsulations efficiently with extendibility is very important, as we have not just MPLS, but SR-MPLS, SRv6 also being deployed in the same network. The fact that BGP-CT uses the same encoding as BGP-LU is a big limitation.

·         Following the discussions during the IDR sessions and the list, the CT solution for multipathing appears to have basic control and forwarding design issues – if it needs to signal multiple routes for the same LSP. What is the purpose of flooding this duplicate information to all nodes ?
NOTE: BGP CAR already has implementations by multiple vendors, with successful interop.
Thanks

Regards … Zafar

From: Idr <[e-mail]> on behalf of Susan Hares <[e-mail]>
Date: Wednesday, July 6, 2022 at 2:16 PM
To: "[e-mail]" <[e-mail]>
Subject: [Idr] Part 2 of CAR/CT Adoption call (7/6 to 7/20) - Adoption of draft-dskc-bess-bgp-car-05.txt and draft-kaliraj-idr-bgp-classful-transport-planes-17.txt

This begins a 2-week WG Adoption call (7/6/2022 to 7/20/2022) for the following drafts:

·         draft-dskc-bess-bgp-car-05.txt

(https://datatracker.ietf.org/doc/draft-dskc-bess-bgp-car/)

·         draft-kaliraj-idr-bgp-classful-transport-planes-17.txt

(https://datatracker.ietf.org/doc/draft-kaliraj-idr-bgp-classful-transport-planes/)
The associated drafts may be useful in your consideration.
CAR:

·         draft-ietf-spring-segment-routing-policy-22

https://datatracker.ietf.org/doc/ draft-ietf-spring-segment-routing-policy/



·         draft-ietf-idr-segment-routing-te-policy-18

https://datatracker.ietf.org/doc/ draft-ietf-idr-segment-routing-te-policy/



·         draft-dskc-bess-bgp-car-problem-statement-05.txt

https://datatracker.ietf.org/doc/draft-dskc-bess-bgp-car-problem-statement/
CT

·         draft-hegde-spring-mpls-seamless-sr-06.txt

https://datatracker.ietf.org/doc/draft-hegde-spring-mpls-seamless-sr/



·         draft-kaliraj-idr-multinexthop-attribute-02.txt

(https://datatracker.ietf.org/doc/draft-kaliraj-idr-multinexthop-attribute/)



·         draft-kaliraj-bess-bgp-sig-private-mpls-labels-04

(https://datatracker.ietf.org/doc/draft-kaliraj-bess-bgp-sig-private-mpls-labels/)


You may discuss adoption of one or both the main drafts (CAR or Classful-Transport (CT)) in your response, and the associate drafts.
A few caveats on your discussion:

1.       Please do not worry whether the drafts belong in BESS or IDR.

Both BESS and IDR work on creating relevant quality standards in BGP,

and the chairs will work this out.



2.       The IDR has spent time over 2020-2022 discussing these drafts.

For background information, see the following links below.

You can refer to these previous presentations or email discussions in your responses.



3.       Please constrain your discussion to whether these drafts should be adopted.

I’ve started another email thread on whether path establishment/distribution

for a color (aka QOS/SLA/Transport Class) should be done via a

specific BGP route (i.e., per-color NLRI) rather than as per-color attributes on a route.
https://mailarchive.ietf.org/arch/msg/idr/FhoK04HsSy9tR7ioV7AD0Vv6Ir4/

Questions (to consider) for these drafts:
Jeff Haas (IDR Co-chair) posted a summary on March 21, 2022 that for
route resolution and route origination/propagation, BGP-CAR and BGP-CT are functionally identical,
but operationally different.
    ( https://mailarchive.ietf.org/arch/msg/idr/e69NRd9i2aG0WUxFkShEfQHZsHo/

1.       Do you agree or disagree that these two drafts are functionally identical?

2.       If you agree, should we have just one draft or do the operational difference encourage us to have two drafts?

3.       If you disagree, do the functional differences encourage us to have one or two drafts adopted?