Skip this Video
Download Presentation
Network Power Management Fundamentals

Loading in 2 Seconds...

play fullscreen
1 / 21

Network Power Management Fundamentals - PowerPoint PPT Presentation

  • Uploaded on

Network Power Management Fundamentals. Bob Combs Lead Program Manager Microsoft Corporation Narsi Nagampalli Software Development Lead Microsoft Corporation. Agenda. PC power usage Vista power management Goals for Windows 7 power management Feature enhancements

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Network Power Management Fundamentals' - jennica

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
network power management fundamentals

Network Power Management Fundamentals

Bob Combs

Lead Program Manager

Microsoft Corporation

Narsi Nagampalli

Software Development Lead

Microsoft Corporation

  • PC power usage
  • Vista power management
  • Goals for Windows 7 power management
  • Feature enhancements
  • Demo Wake-on-LAN in Windows 7
  • Configuration and administration
  • Logo requirements
energy awareness for pcs
Energy Awareness for PCs
  • Energy costs are rising
  • PC energy consumption has doubled since 2000
    • EPA estimates PCs use ~2% of all electricity consumed
  • Businesses trimming costs
  • Home users are thinking “green”
    • PC on 24/7 is 8% of household power usage

100 -


Power (watts)


50 -



0 -





sleeping pc equals real savings
Sleeping PC Equals Real Savings
  • PC sleeping 14 hours per day saves 598–760 kWh per year
  • Approximately $63,500 per year for 1,000 PCs
  • Saves 420-534 kg of CO2 from energy production (~1/10 of average auto)
wake on lan in vista
Wake-on-LAN in Vista
  • Wake-on-LAN (WoL) off by default
  • Wake patterns
    • Magic packet
    • Directed layer2 packet
    • NetBIOS name query packet
    • IPv4 Address Resolution Protocol (ARP) request packet
    • IPv6 Neighbor Solicitation (NS) packet
vista wol observations
Vista WoL Observations
  • Wake patterns don’t account for different network environments
  • Spurious traffic in enterprise environment can continually wake machines
    • Directed packets
    • Switches refreshing their tables
    • Not an issue in home networks
windows 7 power goals
Windows 7 Power Goals
  • PC should sleep when idle
  • Preserve remote availability
  • Reduce energy consumption at runtime
    • Power down devices when not in use
target scenarios
Target Scenarios
  • Media PCs
  • Remote Desktop/Terminal Services
  • File sharing
  • Printer sharing
  • Enterprise maintenance
  • Distributed applications
network wol features in windows 7
Network WoL Features in Windows 7
  • Wake-on-LAN/Wake-on-Wireless LAN (WoL/WoWLAN)
    • On by default
    • Revised set of wake patterns
  • Power management offloads
    • Address Resolution Protocol (ARP) for IPv4
    • Neighbor Solicitation (NS) for IPv6
  • Device low power on media disconnect
wake patterns
Wake Patterns
  • Bitmap patterns
  • Magic packet
  • IPv4 TCP SYN packet type
  • IPv6 TCP SYN packet type
  • 802.1x EAPOL request identity message (wireless) packet type
network presence offloads when the system is asleep
Network Presence Offloads When the System is Asleep
  • ARP request processing in the NIC
    • Responds to IPv4 address resolution requests with the host MAC address
    • No ARP caching/management
  • NS processing in the NIC
    • Responds to IPv6 Neighbor Solicitation requests with the host MAC address
    • Supports public, link-local, and temporary IPv6 addresses
wake patterns according to network environment
Wake Patterns According to Network Environment
  • Determined by location: Home vs. work
  • Magic Packet is a common wake pattern
  • TCP SYN IPv4/IPv6 indicates new connection requests; e.g., file sharing
  • Wake for name resolution requests
    • NetBIOS – IPv4 only
    • LLMNR – environments without DNS
  • ARP, NS – if no offloads available
low power on media disconnect
Low Power on Media Disconnect
  • While PC is in system working state (S0)
  • On LAN cable disconnect, the NIC is placed in device sleep (D3)
  • On LAN cable reconnect, the NIC into working state (D0)
  • If the system goes to sleep while the cable is disconnected, this feature is canceled
keywords added for windows 7
Keywords Added for Windows 7
  • Finer control of capabilities
  • User can access from Device Properties
  • Programmatic change using WMI
configuration and administration
Configuration and Administration
  • WMI interfaces to query and set configuration settings
    • Configuration of systems
    • Global administration
    • Management applications
  • WMI interfaces to query current and hardware capabilities
    • 3rd party applications
    • Diagnostics
network logo requirements
Network Logo Requirements
  • WoL logo
    • Must support at least 6 WoL patterns
    • By 2010, must support at least 8 WoL patterns
  • Network presence offloads
    • Support ARP and NS optionally
    • ARP and NS offloads required by 2010
call to action
Call To Action
  • Update hardware and drivers to NDIS 6.20 to take advantage of new Windows 7 functionality
  • Provide support for at least 8 wake patterns
  • Implement ARP and NS power management offloads on NIC
  • Support new packet type patterns
  • Support low power on media disconnect
additional resources
Additional Resources
  • Windows 7 WDK available with Beta
  • Released DDI is available on MSDN:
  • Device driver questions
  • Windows Logo Program Web site:
  • Related Sessions
    • COR-T525 Network Device Overview
    • COR-T540 Windows 7 Power Management Overview
    • ENT-T551 Windows Server Power Management Overview
© 2008 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.

The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.