The Green Abstraction Layer
A Standard Power-Management
Interface for Next-Generation Network
Devices
By group 8
1
Agenda

Introduction

Motivation

GAL

Power management primitives

Process

Architecture

Summary
2
Introduction

GAL- Interface between high level algorithms
and lower level representing hardware

Energy management in network using physical
resources
3
Motivation

Increase power consumption and energy costs
over time

Increased user traffic and router capacities

Network operates at maximum capacity
4
GAL aims




Network control plane to access devices green
networking capabilities.
Represent the power-management capabilities
available in heterogeneous data plane hardware;
A framework for information exchange between
power-managed data plane entities and control
processes
A reference control chain enabling a consistent,
hierarchical organization of multiple local and
network-wide energy-management protocols.
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Management concepts

PMP let operators modulate energy consumption of
network devices and subsystems

Invoke PMPs to provide QoS with minimum power

Giving each network device its own independent
control algorithm which implement a network control
policy(NCP)
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Types of Power Management
Primitives(PMPs)

Standby : freeze most functionalities =>low energy states,
fast wake-up times

Power scaling : dynamically change the working rate of
the component
Energy-Aware States (EAS)

Power setting that can be configured through the GAL

Provides trade off between power consumption and n?W
performance
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Control Policies


a)
b)
c)
Network control policy (NCP): recent suggestion
Three aspects of reducing consumption:
by moving traffic flows among alternative network
paths, some nodes+subsystems(e.g. OSPF-TE)
NCPs > LCPs, but has two drawbacks(higher
feedback/convergence delays+unwareness of
mapping entities)=>overcome them
capture hardware nuances
=>motivate a strategy of jointly adopting LCPs+NCPs
to optimize energy consunmption in a hierarchical
way
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Purpose

To hide implementation details of energy-saving
approaches

To provide standard interfaces for interactions
between green hardware and its control framework
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Feature

Hierarchical view of device’s organizations

Components at various levels as a tree
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Function

Provide energy-aware capabilities

Entities can trade off power consumption
and performance
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Process

The lowest level

PMPs require specific LCPs to directly manage

GAL’s top level instance used here for
interfacing such energy-aware entities
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Process (Contd.)

The intermediate level

New LCPs are needed to orchestrate entities’
settings

Expose a synthetic set and available
configurations to higher levels

Terminates at the device level
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Process (Contd.)

The highest level

Highest LCPs orchestrates the device’s highlevel configuration

Expose a simplified view to NCPs
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Hierarchical tree

Root nodes: LCPs and control apps

Leaf nodes:
hardware elements
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Why leaf nodes reside at
different levels

Some energy-aware entities need to be accessible from
higher levels

Some manufactures would rather not expose
subcomponents’ internal organization and hardware
architecture
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Specific presentations
1. Entity 1’s LCP selects the chassis containing the
the physical port bound to the logical link
2. The chassis’s LCP(entity1.2) forwards the
command to the corresponding line card (entity
1.2.2), and reduces the fans’ speed
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Specific presentations(contd.)
3. If no other links active, the layer-3 LCP sends
the entire line card to sleep
4. Otherwise, the LCP puts the physical interface
into standby mode and reduce the performance of
all hardware components that process packets for
that port
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GSI

Green standard interface

A lightweight interface for managing energy-aware
hardware entities

Provide a set of functions and data types for GAL
interface
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GSI (contd.)

Discovery : retrieves information about available
EASs and other information about an entity

Provisioning : allows control processes to set an EAS
to an entity

Monitoring : of the physical device’s relevant
parameters

GSI can interface with any network protocol, e.g.
SNMP
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Summary

GAL provide a simple standard interface for
representing the energy-aware capabilities of
network devices to higher-level protocols

Features multilayered abstract model
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Reference

R. Bolla, R. Bruschi, F. Davoli, L. D. Gregorio, P.
Donadio, L. Fialho, A. Lombardo, D. Reforgiato,
and T. Szemetby, "The Green Abstraction Layer: A
Standard Power Management Interface for NextGeneration Network Devices," submitted to the
IEEE Internet Computing Magazine, 2012.

D. Reforgiato, A. Lombardo, F. Davoli, L. Fialho, M.
Collier, P. Donadio, R. Bolla, R. Bruschi, "Exporting
Data-Plane Energy-Aware Capabilities from
Network Devices toward the Control Plane: The
Green Abstraction Layer “, IEEE, 2012

The ECONET Project: Green Abstraction Layer,
http://www.econetproject.eu/Public/Description/3
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