Communicator QoS DSCP Marking on x64 Operating Systems

I never did manage to figure this one out. The registry key HKLM\Software\Microsoft\RTC\Transport\QoSEnabled=1 never seemed to take effect on x64 versions of Vista or Windows 7. Wireshark packet traces would show no tags, but x86 clients worked just fine. Turns out the registry key you need to set for this to work is under the WoW6432Node which makes a ton of sense after seeing it. The DWORD you need to set is this one:


Thanks to Matt McGillen for posting this originally.


Recent content I've written for you—just for you!— to enjoy while you're here.


Quick commentary and links to other sources you'll find interesting. I promise.


Some personal background, links to related projects, and other ways to connect.

Hi there. My name is Tom Pacyk and this is my small home on the web. I love the intersection of design, technology, and communication, which is a combination that led me to a career in sales and marketing roles at places like Zoom and ServiceNow. They're a bit old now, but I also had the opportunity to publish a couple of books along the way.

Portland, Oregon is home for me, my wife Beth, and our three kids, but I'm actually a Midwestern transplant—I grew up in the Chicago suburbs and went to school at Purdue and Illinois. When I find some free time I'm probably going to concerts, rooting for the Portland Timbers, or working on my Sunshine Burn Photography project.