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In Windows I have QoS checkbox (selected by default) along with ipv4 etc. What is that? Should I turn it off if I don't need QoS? Does it occupy resources?

Oleg Vazhnev
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1 Answers1

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It's Quality of Service, it prioritizes certain traffic.

As in Windows 2000, programs can take advantage of QoS through the QoS APIs in Windows XP. One hundred percent of the network bandwidth is available to be shared by all programs unless a program specifically requests priority bandwidth. This "reserved" bandwidth is still available to other programs unless the requesting program is sending data. By default, programs can reserve up to an aggregate bandwidth of 20 percent of the underlying link speed on each interface on an end computer. If the program that reserved the bandwidth is not sending sufficient data to use it, the unused part of the reserved bandwidth is available for other data flows on the same host.

There is a tweaking guide here.

Lucas Kauffman
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  • so what? should I turn it off? what is a use case when QoS may be helpful? – Oleg Vazhnev Mar 20 '12 at 20:44
  • Like when using voice over IP applications, suggest you are downloading something (using the whole bandwith) and you start using skype, you will lag. When you use QoS the skype traffic will be prioritized and you will have a clean chat. It's not only for skype but also for SSH traffic, RDP, ... – Lucas Kauffman Mar 20 '12 at 20:46
  • so on server that normally run single application I assume I can disable that... – Oleg Vazhnev Mar 20 '12 at 20:50
  • well it can be handy actually, if your application is taking a beating of bandwidth and it's turned off, it might be hard to get into your windows machine (or very slow). If you don't mind that, you can turn it off I guess... – Lucas Kauffman Mar 20 '12 at 20:52
  • I go to my machine via another internet-connected interface that I never use for anything else.... – Oleg Vazhnev Mar 21 '12 at 07:07