Re: [Detnet] New Version Notification for draft-liu-detnet-large-scale-requirements-03.txt

[Peng Liu <[e-mail]>]

Hi Lou,

Thanks for your comments. We think the large-scale deterministic network aims at the wide area network, which may also has more network devices, detnet flows and cross multi domains. Those characteristics bring more challenges to ensure the detnet service.

As you said, the current version is not clear about what large-scale is, and it is inaccurate to say like 'detnet is limited to a single network domain'. So we propose the modification at the last paragraphs in the Introduction Section:

A large-scale network usually has a longer transmission distance, more network devices and more kinds of traffic flows than a Local area network. It also has the characteristics including:
The link delay between network nodes is larger. The end to end path is a combination of short and long distance hops. The path between two neighbor nodes can be asymmetric in terms of the link delay. There are many types of network nodes which may introduce disparate local time variation and buffering capabilities. At the same time, there are various transmission rate supported at the different ports and on different network node, varying from tens of Mbps to tens of Gbps or higher. A large number of flows can travel across multiple Detnet domains. 
 
Such domains are normally within a single administrative control network or multiple cooperating administrative networks within a closed group of administrative control [RFC8655]. However they may belong to different AS domains and be controlled by multiple peering or cascaded controllers, and at the same time they may not have the same time clock source. Maintaining per flow status becomes impractical in the large scale network. Aggregation and disaggregation of flows take place at the boundaries of Detnet domains as well as within a Detnet domain with various rules. The flow identification and packet treatment should take care of one or combined changes introduced by the large-scale network.  

This document describes requirements for large-scale deterministic networks which demands the enhancement based on the existing bounded latency mechanisms and the corresponding data plane to ensure the detnet service for single administrative network or multiple (cooperating) administrative networks that defined in the detnet charter. The deterministic network for open internet is not within current scope.

Moreover, we will remove/refine the uncorrect description related to the multi domains in the whole text. 

Hope that could address the issues about the 'large-scale' and 'multi domain'. 

Thanks again~
Peng&co authors


[e-mail]
 
From: Lou Berger
Date: 2022-09-24 00:52
To: Peng Liu; draft-liu-detnet-large-scale-requirements
CC: DetNet WG
Subject: Re: [Detnet] New Version Notification for draft-liu-detnet-large-scale-requirements-03.txt
Authors,

Thank you for this update. I have a few comments on this draft:

- The first question I have is what is the documents definition of "large-scale deterministic network"?

In the abstract you seems to imply that "large-scale" translates to "wide area":
   ... this document
   describes the technical and operational requirements when the
   different deterministic levels of applications co-exist and are
   transported over a wide area.  

But the intro, you seem to state that "large-scale" translates to "multiple domains":

  ... The current DetNet is limited to a
   single administrative domain network, and there are technical
   elements necessary for application to a large-scale network spanning
   multiple domains.

   This document describes requirements for large-scale deterministic
   networks where different deterministic levels of applications co-
   exist and large-scale deterministic networking across multiple
   administrative domains is possible. 

Can you clarify as well as ensure you are consistent within the document?

FWIW, based on the later sections of the document, I suspect large-scale is used in the document to cover number of flows supported on a device and/or network, as well as longer latency of a link and/or across the detnet domain. No matter what, the document really needs to be explicit.

- The following implies that detnet works only within a single network domain.  I think it would be good to clarify how you define "single *network* domain" in the context of this document.

   DetNet, of which architecture is defined in RFC 8655 [RFC8655],
   provides a capability to carry specified unicast or multicast data
   flows for real-time applications with extremely low data loss rates
   and bounded latency within a network domain.  

Note that the charter says multiple (cooperating) networks that have different administrative control was part of the scope of initial detnet definition, and RFC  8655  defines a "DetNet domain" that is independent from areas/groups/domains of administrative control.
 
- I think the following should be aligned with however you address the previous comment:
   .. As documented in RFC 8578 [RFC8578],
   the scope of networks addressed by the current DetNet is limited to
   networks that can be centrally controlled, i.e., an "enterprise" (aka
   "corporate") network, excluding "the open Internet," explicitly.

RFC 8578 defines *example* use cases.  The appropriate reference for current DetNet *solution* scope is RFC8655 or the other solution oriented documents.  DetNet solutions are not currently limited to central control, enterprise, or corporate networks.  I do agree that the open internet is not within current scope.

   ..The current DetNet is limited to a
   single administrative domain network, and there are technical
   elements necessary for application to a large-scale network spanning
   multiple domains.

As previously noted, the current definition of DetNet is limited to networks that are under a single administrative control or within a closed group of administrative control.

I think clarifying these points would be very helpful (and are necessary) to evaluate the remainder of the document.


Thank you,
Lou (as contributor)

On 8/17/2022 4:50 AM, Peng Liu wrote:
Dear All,

We have posted the new version of draft-liu-detnet-large-scale-requirements-03 based on the discussions and suggestions, and we would like to thanks Bala'zs, Tianran and Fan for their comments. Here are the the major changes:
 
1. Add some descriptions of the requirements and clarifications not to specify solutions in Section 4.
2. Change the name of Section 5.2 as "Support Information used by Functions ensuring Deterministic Latency".
3. Add some clarifications text in Section 5.1 and Section 5.2.
4. Add Shiyin Zhu as the co author and Lei Zhou as the contributor.
5. Correct some formatting and spelling errors.
 
Most of the solution draft presented in IETF 114 reference this document as the base requirement draft. We tried to put the common requirements together and made some updates here. There were around 20 people showing they had read the document during 114 session polling. We think it is a reasonable number to use this draft as the starting point for the milestone of Enhanced DetNet Data Plane Requirements document.
So we encourage the group to review the document. We plan to ask for a call for adoption maybe next month upon chairs’ agreement.

Regards,
Peng&co authors


[e-mail]
 
From: internet-drafts
Date: 2022-08-17 15:51
To: Jeong-dong Ryoo; Peng Liu; Quan Xiong; Shiyin Zhu; Toerless Eckert; Yizhou Li; zhushiyin
Subject: New Version Notification for draft-liu-detnet-large-scale-requirements-03.txt
 
A new version of I-D, draft-liu-detnet-large-scale-requirements-03.txt
has been successfully submitted by Peng Liu and posted to the
IETF repository.
 
Name: draft-liu-detnet-large-scale-requirements
Revision: 03
Title: Requirements for Large-Scale Deterministic Networks
Document date: 2022-08-17
Group: Individual Submission
Pages: 18
URL:            https://www.ietf.org/archive/id/draft-liu-detnet-large-scale-requirements-03.txt
Status:         https://datatracker.ietf.org/doc/draft-liu-detnet-large-scale-requirements/
Htmlized:       https://datatracker.ietf.org/doc/html/draft-liu-detnet-large-scale-requirements
Diff:           https://www.ietf.org/rfcdiff?url2=draft-liu-detnet-large-scale-requirements-03
 
Abstract:
   Aiming at the large-scale deterministic network, this document
   describes the technical and operational requirements when the
   different deterministic levels of applications co-exist and are
   transported over a wide area.  This document also describes the
   corresponding Deterministic Networking (DetNet) data plane
   enhancement requirements.
 
                                                                                  
 
 
The IETF Secretariat
 
 

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