Internet-Draft YANG Power Management September 2023
Li & Bonica Expires 29 March 2024 [Page]
Workgroup:
IVY Working Group
Internet-Draft:
draft-li-ivy-power-00
Published:
Intended Status:
Standards Track
Expires:
Authors:
T. Li
Juniper Networks
R. Bonica
Juniper Networks

A YANG model for Power Management

Abstract

Network sustainability is a key issue facing the industry. Networks consume significant amounts of power at a time when the cost of power is rising and sensitivity about sustainability is very high. As an industry, we need to find ways to optimize the power efficiency of our networks both at a micro and macro level. We have observed that traffic levels fluctuate and when traffic ebbs there is much more capacity than is needed. Powering off portions of network elements could save a significant amount of power, but to scale and be practical, this must be automated.

The natural mechanism for enabling automation would be a Yet Another Next Generation (YANG) interface, so this document proposes a YANG model for power management.

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.

Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress."

This Internet-Draft will expire on 29 March 2024.

1. Introduction

Network sustainability is a key issue facing the industry. Networks consume significant amounts of power at a time when the cost of power is rising and sensitivity about sustainability is very high. As an industry, we need to find ways to optimize the power efficiency of our networks both at a micro and macro level. We have observed that traffic levels fluctuate and when traffic ebbs there is much more capacity than is needed. Powering off portions of network elements could save a significant amount of power, but to scale and be practical, this must be automated.

The natural mechanism for enabling automation would be a Yet Another Next Generation (YANG) interface, so this document proposes a YANG model for power management.

[RFC8348] already provides a model for server hardware management, but does not naturally extend to routers and other network elements. That gap is currently being addressed by [I-D.wzwb-opsawg-network-inventory-management] and [I-D.ietf-ccamp-network-inventory-yang]. This document extends the work presented there to include power management.

This initial draft only provides a tree representation. When there is rough consensus on the tree represetnation, the details of the model will be fleshed out.

1.1. Requirement Language

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “NOT RECOMMENDED”, “MAY”, and “OPTIONAL” in this document are to be interpreted as described in BCP14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.

2. Power Management Elements

The models mentioned above already model a router or network element as a set of components. The details of those components are left to the specific implementation and can be at any level of specificity. Thanks to this flexibility, it is necessary and sufficient that we characterize power management relative to components.

The elements defined below allow management entities to understand how much power each component is using and whether the component can be placed into a ‘power-save’ mode where it would consume less power. Another element allows the management plane to put the component into power-save mode.

2.1. Power consumption

  • Name: used-power
  • Node Type: leaf
  • Data Type: uint32
  • Description: Power drawn by the component, in watts.

This node is applied to components in the model. If an accurate dynamic power measurement is not available, then static power estimates are acceptable.

2.2. Power control capability

  • Name: power-save-capable
  • Node Type: leaf
  • Data Type: boolean
  • Description: True if the component can be put into power-save mode.

2.3. Power control

  • Node: power-save
  • Node Type: leaf
  • Data Type: Boolean
  • Description: True if the component is in power-save mode.
  • Access: Read/write

3. Functional Dependencies

Most inventory models have a hierarchy of components. This hierarchy reflects the physical structure of the system (e.g., a line card can physically contain a port).

With regard to physical containment, components maintain a one-to-many relationship. That is, Component A can contain many other components, including Component B. However, component B can be contain by only one component (i.e., Component A.)

However, legacy inventory models do not reflect functional dependencies. Specifically, they do not indicate which components obtain services from, and therefore depend, components other than their container. Because funtional dependencies are relavant to power management, they are included in the proposed model.

With regard to functional dependencies, components maintain a many-to-many relationship. That is, a component can reuire on many components and be required by many other components.

Functional dependencies may be updated dynamically.

3.1. Required Components

This container holds a list of components that the component uses. For example, a linecard uses a set of switch cards, so the switch cards would be required components. If the bandwidth used by the linecard changes, then the set of switch cards that are required may change dynamically.

  • Node: required-components
  • Node Type: list
  • Description: A list of other components that are required for this component to operate.

3.2. Dependent components

This container holds a list of components that are used by this component. For example, a switch card is used by a set of line cards, so the line cards would be dependent components. This list can also change dynamically.

  • Node: dependent-components
  • Node Type: list
  • Description: A list of other components that are used by this component.

4. Tree Representation

 +--ro component* [uuid]
    +--ro uuid                          yang:uuid
    +--ro used-power?                   uint32
    +--ro power-save-capable?           boolean
    +--rw power-save?                   boolean
    +--ro required-components*          -> ../uuid
    +--ro dependent-components*         -> ../uuid

5. Security Considerations

YANG provides information about and configuration capabilities to the network management plane. Other mechanisms already exist that help secure these interactions. This document extends the scope of what can be controlled by the management plane, but creates no new access paths.

6. IANA Considerations

This document makes no requests for IANA.

7. Normative References

[RFC8348]
Bierman, A., Bjorklund, M., Dong, J., and D. Romascanu, "A YANG Data Model for Hardware Management", RFC 8348, DOI 10.17487/RFC8348, , <https://www.rfc-editor.org/info/rfc8348>.
[I-D.wzwb-opsawg-network-inventory-management]
Wu, B., Zhou, C., Wu, Q., and M. Boucadair, "A Network Inventory Management Model", Work in Progress, Internet-Draft, draft-wzwb-opsawg-network-inventory-management-03, , <https://datatracker.ietf.org/doc/html/draft-wzwb-opsawg-network-inventory-management-03>.
[I-D.ietf-ccamp-network-inventory-yang]
Yu, C., Belotti, S., Bouquier, J., Peruzzini, F., and P. Bedard, "A YANG Data Model for Network Hardware Inventory", Work in Progress, Internet-Draft, draft-ietf-ccamp-network-inventory-yang-02, , <https://datatracker.ietf.org/doc/html/draft-ietf-ccamp-network-inventory-yang-02>.
[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.

Authors' Addresses

Tony Li
Juniper Networks
Ron Bonica
Juniper Networks