Re: [spring] WG Adoption Callfordraft-dong-spring-sr-for-enhanced-vpn

["[e-mail]" <[e-mail]>]

Hi Ran,
 
Thank you very much for your interests in and comments on this draft.

Yes, you are right that SR architecture supports resource related SIDs. So we can specify the resource related framework under SR architecture.  This is the main purpose of this doc. RFC8402 supports resource related SIDs, but doesn't  define them, which are defined in this doc.

However, I am afraid I can not agree with you that this doc is mainly to manage and maintain virtual network resources.  The concept and mechanism of resource-awareness SID is introduced in this doc to enrich the semantics of SR SID and to enhance the SR architecture. Thanks to its flexibility and extensibility.
Resource related SIDs introduced in this doc can be used to construct virtual networks, resource isolated pathes, dedicated queques in one node and so on, which depends on the application scenarios. 

Since this draft belongs to SPRING WG, IMO it is correct that it focuses the semantics and functions associated with SR SIDs. The identifier and mechanisms in control plane could be discussed in the corresponding protocol WGs as next step. Please pay attention to our related work in the protocol WGs and you are welcome to present your comments there. Thanks alot.
 
Best regards,
Zhenqiang Li



[e-mail]
 
From: [e-mail]
Date: 2020-07-20 17:11
To: [e-mail]
CC: james.n.guichard; spring; spring-chairs
Subject: Re: [spring]WG Adoption Callfordraft-dong-spring-sr-for-enhanced-vpn
Hi Jie,
IMO, the essence of the problem is that an identifier should be introduced to manage and maintain virtual network resources,  not whether it is necessary to allocate resource related SIDs , because the current SR architecture already supports resource related SIDs allocation, there is no limit to that. For example, service SID (compuated resource related), Node/Adjacency SID(topological resource related), etc. Especially, SRv6 SID encourages programming anything. Can we say that these SIDs have no resource meaning?
Thus, draft-dong-spring-sr-for-enhanced-vpn does not introduce any new content on the existing SR architecture.

For identifier to manage and maintain virtual network resources, draft-peng-teas-network-slicing firstly to introduce a new identifier (AII) in the network to unifiedly identify the topology, computing and storage resource. Before that, other existing identities only focus on topology resources.

Just for topology related resource, Segment Routing with MTR/Flex-algo/AII all support the division of multiple topological resource, and already support allocatoin of SID per MT-ID/algorithm/AII. Especially for link resource, the bandwidth of the same link can be subdivided into multiple resources. 
If these subdivided resources exist in the form of sub-interface resources, L2-bundles(rfc8668) provides the method to assign adjacency-SID for members, In other words, the allocation of member adjacency SID has already been aware of these subdivided resources, each sub-interface has its own link attributes (bandwidth, delay, etc.). 
If there are no sub-interface, the link can also be shared by multiple virtual networks to allocate multiple adjacency SIDs. Under the existing SR architecture, draft-peng-teas-network-slicing and draft-peng-lsr-algorithm-related-adjacency-sid have already described the allocation of adjacency SID per AII and algorithm.

Obviously, the above SR with MTR/Flex-algo/AII are all complete solutions, including control plane extensions and forwarding mechanisms, and they need not make any changes to the SR architecture.
I wonder according to draft-dong-spring-sr-for-enhanced-vpn, what can we do under its guidance, or what we can't do without this draft? 

Regards,
Ran

原始邮件
发件人：Dongjie(Jimmy) <[e-mail]>
收件人：陈然00080434;[e-mail] <[e-mail]>;[e-mail] <[e-mail]>;
抄送人：[e-mail] <[e-mail]>;
日 期 ：2020年07月16日 19:50
主 题 ：RE: [spring] WG Adoption Callfordraft-dong-spring-sr-for-enhanced-vpn
Hi Ran,
 
Thanks for your comments. While I don’t quite get your point of objection.  Perhaps you have some misunderstanding about the relationship of the drafts mentioned.
 
RFC 8402 introduced the topology and service semantics of SR SID, this document proposed to add resource semantics to SIDs. Then MT or Flex-Algo are control plane mechanism for the distribution of topology-specific SIDs. The relationship with these documents are described in this draft.
        
My reading of draft-peng in LSR and TEAS is that they may provide an option of control plane extensions for the resource-aware SIDs defined in this document, which just proves that the enhancement in this document is in the right direction, and more work based on it could be done in relevant WGs.
 
Thus my suggestion would be to have the SR enhancement adopted in SPRING first, then more discussion about its control plane could happen in other WGs as the next step.  
 
Hope this helps.
 
Best regards,
Jie
 
From: spring [mailto:[e-mail]]On Behalf Of [e-mail]
Sent: Thursday, July 16, 2020 5:20 PM
To: [e-mail]; [e-mail]
Cc: [e-mail]
Subject: Re: [spring] WG Adoption Call fordraft-dong-spring-sr-for-enhanced-vpn
 
Dear WG,
I don't support WG adoption.
It is not a new idea for each Virtual Network to have its own SIDs.
e.g. The earlist description of the SID be allocated per flex-algorithm and related metric
 information was in draft-hegdeppsenak-isis-sr-flex-algo-00(2017.7.17) (now is draft-ietf-isis-sr-flex-algo) . 
The earlist description of the SID be allocated per MT was in draft-filsfils-spring-segment-routing-04(2014.7.3)
(now is RFC8402 ), and draft-peng-lsr-network-slicing-00(2019.2.25) describe the
SID be allocated per AII(alias alice).  For slice resources,https://tools.ietf.org/html/draft-peng-teas-network-slicing-03  
induced slice-id(AII) for slice resources management, and can differentiate them (e.g. L2 link or L3 interface,
section 7 ), and how to compute SR-BE or SR-TE path according to AII combined with other criteria.
 
Regards,
Ran
 

-----Original Message-----
From: spring <[e-mail]> On Behalf Of James Guichard
Sent: Wednesday, July 15, 2020 8:17 PM
To: [e-mail]
Cc: [e-mail]
Subject: [spring] WG Adoption Call for draft-dong-spring-sr-for-enhanced-vpn

Dear WG:

  

This email begins a 2 week WG adoption call for https://datatracker.ietf.org/doc/draft-dong-spring-sr-for-enhanced-vpn/ <https://datatracker.ietf.org/doc/draft-dong-spring-sr-for-enhanced-vpn/>  ending Wednesday 29th July 2020.  

  

Please speak up if you support or oppose adopting this document into the WG. Please also provide comments/reasons for that support (or lack thereof). Silence will not be considered consent.

  

Thanks!

  

Jim, Joel & Bruno

  

  

  


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