Re: [Detnet] Management Plane in draft-malis-detnet-controller-plane-framework-04

["Gengxuesong (Geng Xuesong)" <[e-mail]>]

Hi Bala'zs

Thanks for providing your thoughts! Please find my comments inline.

Best Regards
Xuesong

From: Balázs Varga A [mailto:[e-mail]]
Sent: Thursday, August 27, 2020 12:16 AM
To: Gengxuesong (Geng Xuesong) <[e-mail]>; DetNet WG <[e-mail]>
Cc: 'DetNet Chairs' <[e-mail]>; [e-mail]; Loa Andersson <[e-mail]>
Subject: RE: Management Plane in draft-malis-detnet-controller-plane-framework-04

Hi,

Some views/comments.

Regarding item 1 and 2:
I think OAM is only a portion of the Management plane. As for now, we may simple refer to the
"detnet-x-oam" drafts to avoid confusions.
Just some Management plane related tasks/functions/modules we should cover in the document
in my view:
- administration/collection of DetNet (DN) service requests
- administration/collection of node/network states (variables, counters, etc.) needed for providing a DN service
- tools to design/optimize a DN service (selecting functions to create the service e2e, across the network)
- configuration of nodes for a DN service (e2e, across the network)
- monitoring tools for the e2e DN service
- etc.
All this tasks/functions/modules already exists today but may need some extensions due to the special
requirements/characteristics of DetNet flows.

[Xuesong] All these functions seem very interesting and useful to me, especially when we consider how to deploy DetNet in a real network. Only one concern is about whether these topics are supposed to be discussed in IETF, which I think is highly related to implementation.

Regarding item 3:
I think the "Management plane" part of the document is needed and it should show how the above
listed functionalities are challenged by DetNet, where extension of current solutions is needed. For
example, we may compare the Management plane differences of legacy VPN services and DetNet
service.
Just as an example, we need node internal min/max delay between ingress and egress port pairs
in order to design proper queuing control. This is not relevant for non-DetNet flows, so a new
information element is needed. However, it may be collected using already existing management
plane methods ...

[Xuesong] Good point! I think we could consider to add some descriptions in the following versions.

Cheers
Bala'zs


From: Gengxuesong (Geng Xuesong) <[e-mail]<mailto:[e-mail]>>
Sent: Tuesday, August 25, 2020 9:53 AM
To: DetNet WG <[e-mail]<mailto:[e-mail]>>
Cc: 'DetNet Chairs' <[e-mail]<mailto:[e-mail]>>; [e-mail]<mailto:[e-mail]>; Loa Andersson <[e-mail]<mailto:[e-mail]>>
Subject: Management Plane in draft-malis-detnet-controller-plane-framework-04

Hi WG,

After some great discussions in IETF 108 and offline, I would like to start a thread in the ML to discuss about the management plane of draft-malis-detnet-controller-plane-framework-04, to get consensus in WG . Guidance from WG chairs will also be very helpful.
Background information could be found in the end of the email[*].
Here are some topics that to be discussed:

1.       In IETF 108, a question about "M" is raised: in OAM, "M" represents "Maintenance", but in this document, all the contents about OAM are discussed in a section 5 named "management plane"; This may bring confusion about the terminologies;

2.       In section 5, DetNet OAM is briefly discussed by dividing it into two aspects: OAM for PM and OAM for CFM; while there are two documents in WG covering the same topic: DetNet MPLS OAM and DetNet IP OAM. The relationship between these documents should be considered;

3.       The motivation of DetNet controller plane framework is to analysis the gap between the existing technologies in IETF and DetNet controller plane requirement, and give guidance for further protocol extension or new protocol design. If there have been management plane solutions, whether this part in the document is still necessary.

Best Regards
Xuesong

---
[*]:Here are some background information:

-          WG charter:
Controller Plane: The DetNet Controller Plane is defined in RFC 8655 as "the aggregation of the Control and Management Planes";

-          RFC 8655  Deterministic Networking Architecture
4.4.2.  The Controller Plane
   The Controller Plane corresponds to the aggregation of the Control
   and Management Planes in [RFC7426], though Common Control and
   Measurement Plane (CCAMP) (as defined by the CCAMP Working Group
   [CCAMP]) makes an additional distinction between management and
   measurement.  When the logical separation of the Control,
   Measurement, and other Management entities is not relevant, the term
   "Controller Plane" is used for simplicity to represent them all, and
   the term "Controller Plane Function (CPF)" refers to any device
   operating in that plane, whether it is a Path Computation Element
   (PCE) [RFC4655], a Network Management Entity (NME), or a distributed
   control protocol.  The CPF is a core element of a controller, in
   charge of computing deterministic paths to be applied in the Network
   Plane.

-          RFC 7426  Software-Defined Networking (SDN): Layers and Architecture Terminology
3.4<https://tools.ietf.org/html/rfc7426#section-3.4>.  Management Plane
   The management plane is usually centralized and aims to ensure that
   the network as a whole is running optimally by communicating with the
   network devices' operational plane using a Management-Plane
   Southbound Interface (MPSI) with DAL as a point of reference.
   Management-plane functionalities are typically initiated, based on an
   overall network view, and traditionally have been human-centric.
   However, lately, algorithms are replacing most human intervention.
   Management-plane functionalities [FCAPS<https://tools.ietf.org/html/rfc7426#ref-FCAPS>] typically include:
   o  Fault and monitoring management
   o  Configuration management
-  RFC 7276  An Overview of Operations, Administration, and Maintenance (OAM) Tools
Abstract
   Operations, Administration, and Maintenance (OAM) is a general term
   that refers to a toolset for fault detection and isolation, and for
   performance measurement.