Subject: [Supa] review of draft-ietf-supa-policy-based-management-framework

From: "Marc Blanchet" <[email-masked]>
Date: Mon, 29 May 2017 15:13:51 -0400

Hello,
  some comments on draft-ietf-supa-policy-based-management-framework.
- minor editorial below. search for <MB>. Note that I started to suggest 
to use the present tense instead of the future in the text, but that 
might be related to the point below.
- larger comment: I’m not sure what to do with this document. It looks 
like a large wish list of features. I guess I’m probably too used to 
implementation/protocol details. I guess I will wait until to see the 
actual protocol/yang models.

Regards, Marc.

=====================

Abstract

    Simplified Use of Policy Abstractions (SUPA) defines base YANG data
    models to encode policy, which will point to device-, technology-,
    and service-specific YANG models developed in other working groups.
<MB>I'm not sure having a reference to IETF structure (working groups) 
is appropriate. Because service-specific models could be developed 
outside of IETF wg, or as individual, or as another SDO wg, ...
suggesting: "service-specific YANG models developed elsewhere."
</MB>

…

    Simplified Use of Policy Abstractions (SUPA) will define a generic
<MB>s/will define/defines/</MB>
    policy information model (GPIM) [I-D.ietf-supa-generic-policy-info-
    model] for use in network operations and management applications.
    The GPIM defines concepts and terminology needed by policy 
management
    independent of the form and content of the policy rule.  The ECA
<MB>expand ECA when used first time. Event-Condition-Action (ECA)</MB>
    Policy Rule Information Model (EPRIM) [I-D.ietf-supa-generic-policy-
    info-model] extends the GPIM to define how to build policy rules
    according to the event-condition-action paradigm.

    The EPRIM defines an Event-Condition-Action (ECA) policy

<MB>no need to expand ECA, since it is suggested to be expanded in its 
first use above</MB>

  as an
    example of imperative policies.  An ECA policy rule is activated 
when
    its event clause is true; the condition clause is then evaluated 
and,
    if true, signals the execution of one or more actions in the action
    clause.  This type of policy explicitly defines the current and
    desired states of the system being managed.  Imperative policy rules
    require additional management functions, which are explained in
    section 2.2 below.

…
    The SUPA scope is limited to policy information and data models.
    SUPA will not define network resource data models or network service
<MB>s/will not/does not/</MB>
    data models; both are out of scope.  Instead, SUPA will make use of
<MB>s/will make/makes/</MB>
    network resource data models defined by other WGs or SDOs.

    Declarative policies that specify the goals to be achieved but not
    how to achieve those goals (also called "intent-based" policies) are
    out of scope for the initial phase of SUPA.