QoS in Windows 7

Hello all. My name is Charley. I’m the new QoS program manager for Windows Core Networking.

It has been a while since we posted our last article about QoS. We want to assure you that we’re still committed to improving this technology and building new QoS features in Windows. We received many questions and suggestions from you in the past. We hope you continue doing so because they are important to us.

You probably all know that Windows 7 beta is live and available for you to download. You may wonder what is new in Windows 7 regarding QoS. But before getting to that, I’d like to refresh our memory as to what was new in Windows Vista. In Vista, we introduced two major QoS features: qWAVE and Policy based QoS. qWAVE, or Quality Windows Audio Video Experience, is designed to estimate the network bandwidth, intelligently mark the application packets (with proper DSCP values), and interact with the application in the event of network congestion or fluctuations of available bandwidth (so that the application can take appropriate actions). qWAVE APIs aim to simplify the work of application developers developing QoS-enabled applications for a home network. The APIs are documented in the Windows SDK. In contrast, Policy based QoS has a different target audience. It is intended to enable IT administrators to apply QoS to applications (which don’t need to have native supports of QoS), computers, and users in their enterprise network. It is especially beneficial to an organization with branch offices, where the WAN link capacity is limited and users tend to experience unpredictable network delays when accessing files or applications hosted on the main campus (or a different branch office). If you’d like to know more about these features, we’d suggest you read an excellent article written by Joseph Davies for TechNet magazine. Click here to check it out.

So what’s new in Windows 7? The enhancement we’ve made is called URL based QoS. If you’re familiar with Policy based QoS you know that in Vista an IT administrator can create a policy based on the application name, source and/or destination IP addresses, source and/or destination ports, and the protocol (TCP, UDP, or both). We’ve learned since then that many enterprise applications have been, or will be, hosted on web servers and accessed from a browser, so the IT administrators would love to be able to prioritize or control the network traffic from those web-based applications, provided that a convenient configuration is available. To answer their request, we’ve added a new configuration option: you can create a policy based on the URL of an HTTP server. Say, you host all the training videos of your company on an IIS server running Windows 7 (or more precisely, Windows Server 2008 R2). You can then use a URL based QoS policy to throttle the video traffic (to prevent it from overwhelming your corporate network). Or, you host your company’s CRM or ERP applications on an HTTP application server running Windows 7. You can similarly use a URL based QoS policy to prioritize these applications traffic so that even users at a remote branch office always get prompt replies and have smooth UI experience.

Does this sound interesting to you? Please let us know what you think. In the next blog, we’ll detail the configuration and the rules.

Charley