Huaimo,


Juniper Business Use Only
From: Huaimo Chen <[email protected]>
Sent: Friday, January 28, 2022 2:39 AM
To: Shraddha Hegde <[email protected]>; [email protected]; SPRING WG 
<[email protected]>
Subject: Re: WG adoption call - draft-hu-spring-segment-routing-proxy-forwarding

[External Email. Be cautious of content]

Hi Shraddha,

    Thank you for your comments.

    I remember that I talked to you face to face in IETF meeting and
suggested merging your draft and our draft a long time ago before
your draft is adopted. You said it would be ok to have the two drafts
in WG.
<SH> I honestly don't remember the conversation. I would be OK with two drafts
If the proxy forwarding was adding value but I see that it has no significant 
benefits
As compared to the existing WG adopted draft.


In addition, I sent you an email to ask for merging the two drafts,
but did not receive any reply from you.

    I also remember that Zhibo supported the adoption of your draft.

    These two drafts have some overlaps and differences. Our draft
refers to yours for the overlaps, but focuses on the different
method for protection and the area your draft does not cover.
<SH> BSID protection when anycast is not in use is the area your draft
Covers and is not covered by draft-ietf-spring-segment-protection-sr-te-paths.
proxy forwarding is a solution that overlaps existing solution space and is 
completely different
from existing solution space. For BSID protection, proxy forwarding is not 
necessary.
It can be solved using context tables by learning the details of the BSID from 
neighbors.
It would be good to see how many operators are really interested in this kind 
of BSID protection.


    For example, your draft talks about using anycast SID to protect
node failure. I remember that this was discussed in IETF meeting and
some issues were raised by others.
<SH> There are no open issues AFAIKT.
We do not use anycast SID for
protection.
<SH>The draft draft-ietf-spring-segment-protection-sr-te-paths  proposes
anycast SID as one of the ways to achieve protection (It is the most common 
deployed
mechanisms to achieve protection in SR networks in my knowledge.)

    Regarding to "May cause congestion somewhere else in the network",
this seems true for the two drafts when a node failed.
<SH> The issue I brought up was more for the bandwidth double booking on 
interfaces and it
May happen in proxy forwarding as the proxy forwarder may not lie in the 
shortest path
But may be on the otherside.

Best Regards,
Huaimo

________________________________
From: spring <[email protected]<mailto:[email protected]>> on 
behalf of Shraddha Hegde 
<[email protected]<mailto:[email protected]>>
Sent: Thursday, January 27, 2022 2:15 AM
To: [email protected]<mailto:[email protected]> 
<[email protected]<mailto:[email protected]>>; SPRING WG 
<[email protected]<mailto:[email protected]>>
Subject: Re: [spring] WG adoption call - 
draft-hu-spring-segment-routing-proxy-forwarding


WG,



I  don't support the adoption of this document as a WG document.



I am in agreement with stephane's comments on the list.



1.       May cause congestion somewhere else in the network

There is already WG adopted document that is addressing the problem space

draft-ietf-spring-segment-protection-sr-te-paths.

This draft does not provide significant advantages over the proposed solutions 
in

draft-ietf-spring-segment-protection-sr-te-paths.

draft-hu-spring-segment-routing-proxy-forwarding claims to provide better 
solution when all nodes

have not been upgraded. draft-hu-spring-segment-routing-proxy-forwarding 
introduces protocol extensions

and the nodes that aren't upgraded to understand the extensions will drop the 
traffic so there isn't

any significant improvement in the approach.



In fact, the approach described in 
draft-hu-spring-segment-routing-proxy-forwarding may

cause other issues such as bandwidth double booking since it proposes that  any 
neighbor that

claims proxy forwarding will be used to forward the protected traffic.



For ex:



[cid:[email protected]]



In above diagram

SR-TE path is RT1->RT3->RT7->RT5

Only RT4 supports proxy-forwarding

On failure of RT3, RT1 would send traffic to RT4 via RT1->RT6->RT7-RT4

RT4 will then send to RT7 as per the SR-TE path

RT7 will then send to RT5 via RT7->RT4->RT5



In this example, same traffic is traversing the RT7->RT4 link 3 times.



Operationally this solution is very complex to manage. A network that starts 
with no segment protection,

It may be ok to drop the traffic if some nodes have not been upgraded but 
causing congestion

somewhere else would be difficult to debug.



2.       BSID solution

draft-ietf-spring-segment-protection-sr-te-paths does not explicitly discuss 
the solution for BSIDs.

Most of the BSID deployments use anycast based solution where same BSID is 
assigned on anycast nodes and BSID is always preceded by the anycast SID. 
Section 2.2 in draft-ietf-spring-segment-protection-sr-te-paths discusses this 
approach.

             draft-hu-spring-segment-routing-proxy-forwarding  provides a 
protection solution for BSIDs when anycast is not in use.



 If WG is inclined to solve the BSID protection problem when anycast solution 
is not in use, I would prefer the

              Approach to be more aligned with 
draft-ietf-spring-segment-protection-sr-te-paths. I do not support Introducing 
completely   different solution based on proxy forwarding which has other 
implications described in point 1.





Rgds

Shraddha





Juniper Business Use Only

From: spring [email protected]<mailto:[email protected]> On Behalf 
Of [email protected]<mailto:[email protected]>
Sent: Thursday, January 13, 2022 3:49 PM
To: SPRING WG <[email protected]<mailto:[email protected]>>
Subject: [spring] WG adoption call - 
draft-hu-spring-segment-routing-proxy-forwarding



[External Email. Be cautious of content]



Dear WG,



This message starts a 2 week WG adoption call, ending 27/01/2022, for 
draft-hu-spring-segment-routing-proxy-forwarding

https://datatracker.ietf.org/doc/draft-hu-spring-segment-routing-proxy-forwarding/<https://urldefense.com/v3/__https:/nam11.safelinks.protection.outlook.com/?url=https*3A*2F*2Furldefense.com*2Fv3*2F__https*3A*2Fdatatracker.ietf.org*2Fdoc*2Fdraft-hu-spring-segment-routing-proxy-forwarding*2F__*3B!!NEt6yMaO-gk!TWaV4x51MCL2h93fiW-3XI8ElTsP963AWA5gjKCMU6g9E1WN0cRkqV6D5Qi50WbR*24&data=04*7C01*7Chuaimo.chen*40futurewei.com*7Cf11b3573b9f441267f6008d9e164cfef*7C0fee8ff2a3b240189c753a1d5591fedc*7C1*7C0*7C637788645400164200*7CUnknown*7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0*3D*7C3000&sdata=S2*2BmuO29w3Yy*2F3pqvU1A2xByY7xrciCzp*2FUqZfPPUN4*3D&reserved=0__;JSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJSUlJQ!!NEt6yMaO-gk!XMSkGU0Zm98twzSzoy2RDjLw78tzsjdPlxfqK9Lg-anMbxc8t7yOyePOmhMHgiwU$>



After review of the document please indicate support (or not) for WG adoption 
of the document to the mailing list.



Please also provide comments/reasons for your support (or lack thereof) as this 
is a stronger way to indicate your (non) support as this is not a vote.



If you are willing to work on or review the document, please state this 
explicitly. This gives the chairs an indication of the energy level of people 
in the working group willing to work on the document.



Thanks!

Bruno, Jim, Joel

_________________________________________________________________________________________________________________________



Ce message et ses pieces jointes peuvent contenir des informations 
confidentielles ou privilegiees et ne doivent donc

pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce 
message par erreur, veuillez le signaler

a l'expediteur et le detruire ainsi que les pieces jointes. Les messages 
electroniques etant susceptibles d'alteration,

Orange decline toute responsabilite si ce message a ete altere, deforme ou 
falsifie. Merci.



This message and its attachments may contain confidential or privileged 
information that may be protected by law;

they should not be distributed, used or copied without authorisation.

If you have received this email in error, please notify the sender and delete 
this message and its attachments.

As emails may be altered, Orange is not liable for messages that have been 
modified, changed or falsified.

Thank you.
_______________________________________________
spring mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/spring

Reply via email to