Internet DRAFT - draft-contreras-nmrg-clas-evolution

draft-contreras-nmrg-clas-evolution







NMRG                                                       LM. Contreras
Internet-Draft                                                Telefonica
Intended status: Informational                          October 24, 2021
Expires: April 27, 2022


Evolution of Cooperating Layered SDN Architecture including Compute and
                             Data Awareness
                 draft-contreras-nmrg-clas-evolution-00

Abstract

   This document proposes the extension of the Cooperating Layered
   Architecture for Software-Defined Networking (SDN) framework by
   including Compute and Data Awareness.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Cooperating Layered Architecture for Software-Defined
       Networking (CLAS) . . . . . . . . . . . . . . . . . . . . . .   2
   3.  Augmentation of CLAS with Compute and Data Awareness  . . . .   5
     3.1.  Compute Stratum . . . . . . . . . . . . . . . . . . . . .   5
     3.2.  Learning Plane  . . . . . . . . . . . . . . . . . . . . .   5
     3.3.  Extended CLAS architecture  . . . . . . . . . . . . . . .   6
   4.  TODO for next versions of this document . . . . . . . . . . .   7
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   7
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   7
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   Current telecommunication networks are evolving towards a tight
   integration of interconnected compute environments, offering
   capabilities for the instantiation of virtualized network functions
   interworking with physical variants of other network functions,
   altogether constituting services end-to-end.

   Moreover, network operations are complementing the capabilities of
   automation and programmability with the introduction of Artificial
   Intelligence (AI) and Machine Learning (ML) techniques to facilitate
   informed decisions as well as predictive behavior enabling consistent
   closed loop automation.

   It is then necessary to provide a network management framework that
   could incorporate these trends in a smooth manner, structuring the
   different concerns and the interaction among components operating the
   network.

   This document describes the evolution of one of those frameworks,
   named Cooperating Layered Architecture for Software-Defined
   Networking (CLAS) [RFC8597] to include the aforementioned aspects
   into the architecture.

2.  Cooperating Layered Architecture for Software-Defined Networking
    (CLAS)

   [RFC8597] describes an SDN architecture structured in two different
   strata, namely Service Stratum and Transport Stratum.  On one hand,
   the Service Stratum contains the functions related to the provision
   of services and the capabilities offered to external applications.
   On the other hand, the Transport Stratum comprises the functions



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   focused on the transfer of data between the communication endpoints
   (e.g., between end-user devices, between two service gateways, etc.).

   Each of the strata is structured in different planes, as follows:

   o  The Control plane, which centralizes the control functions of each
      stratum and directly controls the corresponding resources.

   o  The Management plane, logically centralizing the management
      functions for each stratum, including the management of the
      control and resource planes.

   o  The Resource plane, that comprises the resources for either the
      transport or the service functions.

   Figure 1 illustrates original CLAS architecture.



































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                                         Applications
                                               /\
                                               ||
                                               ||
         +-------------------------------------||-------------+
         | Service Stratum                     ||             |
         |                                     \/             |
         |                       ...........................  |
         |                       . SDN Intelligence        .  |
         |                       .                         .  |
         |  +--------------+     .        +--------------+ .  |
         |  | Resource Pl. |     .        |   Mgmt. Pl.  | .  |
         |  |              |<===>.  +--------------+     | .  |
         |  |              |     .  |  Control Pl. |     | .  |
         |  +--------------+     .  |              |-----+ .  |
         |                       .  |              |       .  |
         |                       .  +--------------+       .  |
         |                       ...........................  |
         |                                     /\             |
         |                                     ||             |
         +-------------------------------------||-------------+
                                               ||    Standard
                                            -- || --    API
                                               ||
         +-------------------------------------||-------------+
         | Transport Stratum                   ||             |
         |                                     \/             |
         |                       ...........................  |
         |                       . SDN Intelligence        .  |
         |                       .                         .  |
         |  +--------------+     .        +--------------+ .  |
         |  | Resource Pl. |     .        |   Mgmt. Pl.  | .  |
         |  |              |<===>.  +--------------+     | .  |
         |  |              |     .  |  Control Pl. |     | .  |
         |  +--------------+     .  |              |-----+ .  |
         |                       .  |              |       .  |
         |                       .  +--------------+       .  |
         |                       ...........................  |
         |                                                    |
         |                                                    |
         +----------------------------------------------------+




            Figure 1: Cooperating Layered Architecture for SDN





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3.  Augmentation of CLAS with Compute and Data Awareness

   The CLAS architecture was initially conceived from the perspective of
   exploiting the advantages of network programmability in operational
   networks.

   The evolution of current telecommunication services and networks are
   however introducing new aspects to consider.

   o  Consideration of distributed computing capabilities attached to
      different points in the network, intended for hosting a variety of
      services and applications usually in a virtualized manner (e.g.,
      [I-D.contreras-alto-service-edge]).

   o  Introduction of Artificial Intelligence (AI) and Machine Learning
      (ML) techniques in order to improve operations by means of closed
      loop automation (e.g., [I-D.pedro-nmrg-ai-framework]).

   With that in mind, this memo proposes augmentation to the original
   CLAS proposition by adding the aforementioned aspects.

3.1.  Compute Stratum

   For the first aspect, the CLAS architecture is extended by adding a
   new stratum, named Compute Stratum.  The objective is to contain in
   this stratum the control, management and resource planes related to
   the computing part.  As in the other two strata, the mission is to
   make this additional stratum cooperate with the other two in order to
   facilitate the overall service provision in the network.

   With this addition, and in order to be more explicit in the strata
   scope, the previously named Transport Stratum is renamed as Network
   Stratum, representing the fact that this stratum responsibility is
   focused on the overall connectivity supporting the other two strata
   in the architecture.

3.2.  Learning Plane

   A further extension to the original CLAS architecture is related to
   the need of collecting, processing and sharing relevant data from
   each of the considered strata.  With that purpose a Learning Plane is
   proposed to complement the already existing planes per stratum.

   The learning plane will be in charge of handling the data
   specificities of each particular stratum.  Thus, the learning plane
   in the Service Stratum is focused on data relevant to the service as
   defined by the application or service owner, usually in terms of
   service key performance indicators (KPI) [TMV].  Then, the learning



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   plane in the compute stratum concentrates on data related to the
   computing capabilities in use (e.g., CPU load, RAM usage, storage
   utilization, etc) [OpenStack].  Finally, the learning plane in the
   network stratum is in charge of handling the monitoring and telemetry
   information obtained from the network (e.g.,
   [I-D.ietf-opsawg-service-assurance-yang]).

3.3.  Extended CLAS architecture

   Figure 2 presents the augmentation proposed showing the relationship
   among strata.


                                          Applications
                                               /\
                                               ||
         +-------------------------------------||-------------+
         | Service Stratum                     ||             |
         |                                     \/             |
         |  +--------------+     ...........................  |
         |  | Learning Pl. |     . SDN Intelligence        .  |
         |  |              |<===>.                         .  |
         |  +-----/\-------+     .        +--------------+ .  |
         |        ||             .        |   Mgmt. Pl.  | .  |
         |        ||             .  +--------------+     | .  |
         |  +-----\/-------+     .  |  Control Pl. |-----+ .  |
         |  | Resource Pl. |     .  |              |       .  |
         |  |              |<===>.  +--------------+       .  |
         |  +--------------+     ...........................  |
         |                                /\             /\   |
         |                                ||             ||   |
         +--------------------------------||-------------||---+
                          Standard API -- || --          ||
         +--------------------------------||-----+       ||
         | Compute Stratum                ||     |       ||
         |                                \/     |       ||
         |  +----------+    ...................  |       ||
         |  | Learning |    . SDN             .  |  Std. ||
         |  | Plane    |<==>. Intelligence    .  |  API  ||
         |  +-----/\---+    .    +----------+ .  |    -- || --
         |        ||        .    | Mgmt. Pl.| .  |       ||
         |        ||        .  +----------+ | .  |       ||
         |  +-----\/---+    .  | Control  |-+ .  |       ||
         |  | Resource |    .  | Plane    |   .  |       ||
         |  | Plane    |<==>.  +----------+   .  |       ||
         |  +----------+    ...................  |       ||
         +----------------------------------/\---+       ||
                            Standard API -- || --        ||



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                        +-------------------||-----------||-----+
                        | Network Stratum   ||           ||     |
                        |                   \/           \/     |
                        |  +----------+    ...................  |
                        |  | Learning |    . SDN             .  |
                        |  | Plane    |<==>. Intelligence    .  |
                        |  +-----/\---+    .    +----------+ .  |
                        |        ||        .    | Mgmt. Pl.| .  |
                        |        ||        .  +----------+ | .  |
                        |  +-----\/---+    .  | Control  |-+ .  |
                        |  | Resource |    .  | Plane    |   .  |
                        |  | Plane    |<==>.  +----------+   .  |
                        |  +----------+    ...................  |
                        +---------------------------------------+


                   Figure 2: Extended CLAS architecture

4.  TODO for next versions of this document

   This version is a work-in-progress.  Next versions of the document
   will address somo further aspects such as:

   o  Communication between strata (and planes).

   o  Deployment scenarios (including legacy ones).

   o  Potential use cases (specially in alignment with on-going
      activities in NMRG).

5.  Security Considerations

   Same security considerations as reflected in [RFC8597] with regards
   to the strata architecture apply also here.

   Apart from that, the introduction of the Learning plane on the data
   management imposes additional security concerns.  (TODO: elaborate on
   data-related security issues).

6.  IANA Considerations

   This draft does not include any IANA considerations

7.  References







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   [I-D.contreras-alto-service-edge]
              Contreras, L. M., Lachos, D. A., Rothenberg, C. E., and S.
              Randriamasy, "Use of ALTO for Determining Service Edge",
              draft-contreras-alto-service-edge-03 (work in progress),
              July 2021.

   [I-D.ietf-opsawg-service-assurance-yang]
              Claise, B., Quilbeuf, J., Lucente, P., Fasano, P., and T.
              Arumugam, "YANG Modules for Service Assurance", draft-
              ietf-opsawg-service-assurance-yang-01 (work in progress),
              July 2021.

   [I-D.pedro-nmrg-ai-framework]
              Martinez-Julia, P., Homma, S., and D. R. Lopez,
              "Artificial Intelligence Framework for Network
              Management", draft-pedro-nmrg-ai-framework-00 (work in
              progress), October 2021.

   [OpenStack]
              "OpenStack performance documentation",
              https://docs.openstack.org/developer/performance-docs/
              index.html .

   [RFC6241]  Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed.,
              and A. Bierman, Ed., "Network Configuration Protocol
              (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011,
              <https://www.rfc-editor.org/info/rfc6241>.

   [RFC8597]  Contreras, LM., Bernardos, CJ., Lopez, D., Boucadair, M.,
              and P. Iovanna, "Cooperating Layered Architecture for
              Software-Defined Networking (CLAS)", RFC 8597,
              DOI 10.17487/RFC8597, May 2019,
              <https://www.rfc-editor.org/info/rfc8597>.

   [TMV]      "Service performance measurement methods over 5G
              experimental networks", 5G-PPP TMV white paper , May 2021.

Acknowledgments

   The work of L.M.  Contreras has been partly funded by the European
   Commission through the H2020 project 5GROWTH (Grant Agreement no.
   856709).

Author's Address







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   Luis M. Contreras
   Telefonica
   Ronda de la Comunicacion, s/n
   Sur-3 building, 3rd floor
   Madrid  28050
   Spain

   Email: luismiguel.contrerasmurillo@telefonica.com
   URI:   http://lmcontreras.com/










































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