Network Power Management Fundamentals

2. Network Power Management Fundamentals Bob Combs Lead Program Manager Microsoft Corporation Narsi Nagampalli Software Development Lead Microsoft Corporation

3. Agenda • 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

4. 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 - Active Power (watts) Idle 50 - Sleep Off 0 - 0 8760 Hours/year From http://www.energystar.gov/ia/partners/prod_development/revisions/downloads/computer/TierII_Network_Issue_Slides.pdf

5. 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)

6. 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

7. 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

8. Windows 7 Power Goals • PC should sleep when idle • Preserve remote availability • Reduce energy consumption at runtime • Power down devices when not in use

9. Target Scenarios • Media PCs • Remote Desktop/Terminal Services • File sharing • Printer sharing • Enterprise maintenance • Distributed applications

10. 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

11. 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

12. 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

13. 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

14. demo Wake on LAN with Network Presence Offload

15. 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

16. Keywords Added for Windows 7 • Finer control of capabilities • User can access from Device Properties • Programmatic change using WMI

17. 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

18. 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

19. 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

20. Additional Resources • Windows 7 WDK available with Beta • Released DDI is available on MSDN:http://msdn.microsoft.com • Device driver questions • NDIS 6 Feedback alias: ndis6fb@microsoft.com • Windows Logo Program Web site:http://www.microsoft.com/whdc/winlogo/default.mspx • Related Sessions • COR-T525 Network Device Overview • COR-T540 Windows 7 Power Management Overview • ENT-T551 Windows Server Power Management Overview

21. © 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.