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Link Layer Topology Discovery And Enabling Wi-Fi Diagnostics For Network Performance Tuning

Link Layer Topology Discovery And Enabling Wi-Fi Diagnostics For Network Performance Tuning. Gabe Frost and Glenn Ward Windows Core Networking Microsoft Corporation. What You’ll Learn. Top issues impacting user experience and perception of product quality (Wi-Fi) Hardware and Software vendors

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Link Layer Topology Discovery And Enabling Wi-Fi Diagnostics For Network Performance Tuning

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  1. Link Layer Topology Discovery And Enabling Wi-Fi Diagnostics For Network Performance Tuning Gabe Frost and Glenn WardWindows Core NetworkingMicrosoft Corporation

  2. What You’ll Learn • Top issues impacting user experience and perception of product quality (Wi-Fi) • Hardware and Software vendors • What to support in WLAN AP to avoid performance degradation • What to support in NIC driver to enable diagnostics for Network Performance Tuning • The role of LLTD and additional value provided

  3. AV-Capable Home Networks • Consumers demand simplicity and reliability • No-new-wires • Focus on WiFi Audio/Video (AV) networks • Consumer Electronics (CE) centric, not Information Technology (IT) centric • Multiple configuration/upgrades is costly • AV networking shouldn’t require an expert • Can’t avoid all problem conditions, so… • Actionable diagnostics necessary to remove “magic” in network setup

  4. Top Issues: No-New-Wires • No-new-wires networks are shared resource • 2.4 GHz WiFi dominant home network • Wireless highly susceptible to performance degradation and non-optimal setup • Backward compatibility for legacy devices • Interference from nearby networks • Microwave, cordless phone, etc. (common RF) • Concurrent use of shared network (cross-traffic) • Distance and obstructions (walls, floors, people) • Setup: Dual-band selection, unsupported topologies • 5 GHz solves most (not all) • Diagnostics provided for each top issue

  5. Diagnostics Business Opportunity • Xbox 360 has built-in Media Center Extender • About 5 million projected sales by June • Significant Xbox WiFi adapter sales • Windows XP Media Center Edition is currently top consumer SKU • Windows Vista Home Premium and Ultimate Editions provide Media Center (no separate SKU/software) • Media Center Extender software licensing and porting kit available for non-Windows • Lineup of Media Center Extenders coming

  6. Network Performance Tuner • Validate and tune network for Media Center Extender (MCX) use (i.e. AV networking) • Verify end-to-end throughput • Can path support Standard Definition (SD)? • High Definition (HD)? • Identify and diagnose WiFi performance degradation on first use and during run-time • Ensure proper network setup before AV use • Inform what caused run-time quality issue • Requires NDIS6 NWF driver on Windows Vista

  7. NPT Integral To Media Center

  8. 2.4 GHz Legacy Compatibility • 802.11g theoretical 54 Mbps not possible • 1/3 feasible in perfect conditions • Legacy 802.11b devices further impact perf • Any associated legacy device reduces bandwidth by ½ or more (not sending data) • Even if not on end-to-end media path Associated Disassociated

  9. Nearby 802.11 Interference • Performance impacted by co-channel and adjacent-channel interference • E.g. 4 Mbps on co-channel will reduce throughput by ~4 Mbps • Impacts Close-proximity dwellings • Default static channel out-of-box exacerbates problem • NPT diagnoses and identifies clearest channel

  10. General RF Interference • Common household interference greatly impacts 2.4 GHz WiFi • 5 GHz (dual-band) AP solves this problem • NPT will identify if causing congestion during run-time Microwave Oven Cordless Phone Connection Loss

  11. Concurrent Network Use • Commonly referred to as cross-traffic • WiFi (2.4 and 5 GHz) is a shared medium, so concurrent use reduces available bandwidth • Impacts all shared mediums, not just WiFi • Examples (contend with ongoing AV streams) • Heavy Internet use • File transfers • Network print or backup • Dual-band AP mitigates this problem • AV on 5 GHz and data-oriented on 2.4 GHz • NPT will identify if causing congestion during run-time • Source of cross-traffic must implement Link Layer Topology Discovery (LLTD)

  12. Detecting Cross-Traffic As Cause Of Congestion(Using LLTD)

  13. Distance And Obstructions • Performance degraded if MCX and AP are separated by walls and floors • Also moving obstructions (people) • Impacts both 2.4 GHz and 5 GHz • NPT will diagnose if causing congestion during run-time

  14. Common Setup Problems • Dual-band AP (5 GHz and 2.4 GHz) available, but connected to 2.4 GHz • NPT detects this situation • Both Media Center and MCX on same radio • Commonly referred to as double-hop • Effectively ½ available bandwidth (or worse) Media Center wired, MCX Wireless Double-Hop (both connected to same WiFi radio)

  15. Link Layer Topology Discovery (LLTD) Glenn WardMicrosoft Corporation

  16. Windows® Rally™ Program Access to Technologies Simple Unified License Technical Guidance

  17. Windows® Rally™ Devices Effortless to configure and maintain Reliable and simple to manage More secure and provide rich digital experiences

  18. Windows Rally Experiences Windows Rally Technologies Applications Management Interfaces Device Specific Drivers Plug and Play Extensions Quality of Service LLTD: QoS Extensions Network Map LLTD: Topology Map Wireless Setup Windows Connect Now Discovery FunctionDiscovery UPnP AV Devices Device Profile for Web Services NetworkedDevices IP Network (IPv4, IPv6) Ethernet/Wireless Windows Rally Experiences Windows Rally Technologies

  19. Problem Statement • Users have difficulties troubleshooting issues on their network • Partners have few support tools for their device and/or service • Home Networks growing in sophistication • Was: Internet Sharing for email, Web surfing • Now and future: Streaming from WAN, cross-home Media Delivery • Latency-sensitive Broadband Services: IPTV, VoIP, Gaming • Unrealized scenarios -> product returns, smaller TAM Home Networking complexity calls for better infrastructure tools

  20. Solved Via Windows Vista Network Map/LLTD • LLTD – Link Layer Topology Discovery • Discovery, Topology and Diagnostics, below Internet Layer • No Dependency on NID intelligence to function • Detect Legacy Hub, Switch, AP, Half-Bridge • Ensures correct problem isolation • Ensures network robustness – bandwidth, cross-traffic detection

  21. Windows Vista UISample Map

  22. Business Value • Raise visibility, perceived value of networks and IP devices! • No longer plumbing component • Device Capabilities Delivery • Identified in UI • Give credit (good/bad) where due • Leverage LLTD as L2 Bootstrapping protocol • Provide you with opportunity to showcase your • Industrial Design • Brand • Device Capabilities

  23. Porting Kit ‘Beta 1’ Contents • Source Code • Reference LLTD implementations • Test Suite • User’s Guide and FAQ • Protocol Spec • Mandatory/Optional call-outs • .ICO creation guidelines

  24. QoS Extensions To LLTD • Provides packet time-stamping for bandwidth and diagnostic experiments • Mandatory if your device handles QoS-sensitive traffic (Audio/Video) • Mandatory component for all Media Center Extender (MCX) devices • E.g. Xbox 360 • Media Center must see sufficient bandwidth • Stream won’t receive priority if poor results returned

  25. Feature OverviewClosing Info • XP Responder: OOB Release • License • No cost, simple licensing terms • Licensees receive LLTD Porting Kit • Questions LLTDinfo @ microsoft.com

  26. Call To Action • IHV: Meet Designed for Windows Gold requirements • Build dual-band WLAN AP • IHV: Download LLTD reference implementation and incorporate into router/AP and media player devices • QoS extensions critical • ISV: Implement NDIS6 Native WiFi (NWF) drivers • All OIDs required by diagnostics are mandatory in NWF • Additionally • Set lRSSI field of DOT_11_RECV_CONTEXT per-packet • NDIS_MINIPORT_ADAPTER_NATIVE_802_11_ATTRIBUTES • Set at initialization time

  27. Additional Resources • Web Resources • Blog http://blogs.msdn.com/wndp • Windows Rally Technologies • Residential gateway implementation guide http://www.microsoft.com/whdc/device/network/homenet/WAP_reqs.mspx

  28. © 2006 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.

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