WiFi WMM Requirements for Vista Miniport Drivers

A number of partners who author wireless drivers for Vista have asked how they can ensure their WiFi Wireless Multimedia (WMM) implementation is correct, so I thought I’d be explicit about this very important topic. To begin, read the 4-part series WiFi QoS Support in Windows Vista, which describes how Vista internally indicates a WMM…


Detecting 802.1p Priority Tags: Part 3

Parts 1 and 2 of this series discussed how to determine whether an 802.1p tag was added to traffic, and how to modify the NDIS light-weight-filter (LWF) sample driver source code to accomplish this task. We do know that you’re all very busy and not everyone is a developer, so we’ve added to the package:…


Detecting 802.1p Priority Tags: Part 2

In Gabe’s last post on detecting 802.1p priority tags, he described at a relatively high-level why it is difficult to detect a priority tag using packet tracing applications, as well as the proper way to determine whether a tag was present in a packet that was sent onto the wire (or air). In this post,…


The Case of Vista Multimedia Playback and Network Throughput

Mark Russinovich has a great post today on the what and how of the network/multimedia vista issue that people have recently been talking about. Amusingly enough a couple people on /. more or less figured it out, but are only modded 3 and lower. Go Figure. — Ari


WiFi QoS Support in Windows Vista: WMM part 2

My previous post on WiFi QoS (WMM) discussed the four access classes (BG, BE, VI, and VO) available for traffic differentiation. I also highlighted that packets containing either a layer-2 802.1p tag or layer-3 DSCP mark (i.e. packets associated with a QoS flow) will be added to the correct WMM access class by a Native WiFi…


WiFi QoS Support in Windows Vista: WMM

In Windows Vista, a great deal of effort has gone into making it simple for network applications to take advantage of QoS capable networks. This post focuses on QoS for WiFi networks (both consumer and enterprise) and how the Vista network stack enables differentiated treatment of outgoing traffic. The WiFi Alliance has created a certification…


The NDIS 6.0 Driver Model

NDIS 6.0 was introduced to the independent hardware vendor (IHV) and developer community at last year’s WinHEC. It brings the promise of greater performance, improved manageability, reduced complexity for NDIS miniports, and simpler models for writing intermediate and filter drivers. Are you curious how much of the promise has been realized?   At WinHEC this…


An Interview with Alireza Dabagh, NDIS development lead

Tell us about what you do in Windows.   I’m NDIS development lead. I lead a team which works on NDIS and related components, and I also contribute to the architecture, coding and design of our components.   How long have you been participating in WinHEC?   Quite some time! Maybe 4 or 5 years….