"Limit 20% to keep bandwidth" FAQ

To improve the speed of the Internet, to do exactly the opposite!

1: In "Run" enter Gpedit.msc, open the Group Policy Editor.

2: Find "Computer configuration → administrative Templates → network →qos Packet Scheduler", select the right "limit to retain bandwidth", double-click to open.

3: Select "Enabled", and the broadband limit below is changed to 85-100

About having a few friends set success, ask me what the principle of the problem is, here is a description: I was with a friend of mine before trying to say "limit to retain bandwidth" disabled to improve the speed of the Internet, found that there is no role, so hold the test of the mentality of trying to turn him higher, only to find that can improve the speed of web browsing ( Note: "Web browsing Speed" rather than "Network download speed", so I don't know the principle. I looked it up on the Internet. I found an explanation for the "limit the bandwidth to retain" feature.

Improve network speed by modifying Group Policy 20% is a scam.

The question of QoS in Microsoft's KB316666 Knowledge Base is explained as follows:

With Windows 20,001, in Windows XP, programs can also leverage QoS through the QoS Application Programming Interface (API). All programs can share a full network bandwidth, with the exception of programs that require bandwidth priority. Other programs can also use this "reserved" bandwidth, with the exception of the requestor that is sending the data. By default, the program retains a cumulative bandwidth of up to 20% of the basic link speed for each interface of the terminal computer. The unused portion of the reserved bandwidth can be used for other data flows on the same host if the bandwidth-preserving program sends the amount of data that is not fully exhausted. In Microsoft's KB316666 it is a mistake to say that many of the published technical articles and newsgroup articles have repeatedly mentioned that Windows XP typically retains 20% of the available bandwidth for QoS.

Let's begin by clarifying what the real meaning of QoS is. The Chinese meaning of QoS is: Networking service quality. Specifically refers to the various communication or program type priority technologies that are applied throughout the network connection. QoS technology exists to achieve better quality of networked services. QoS is a set of service requirements that the network must meet to ensure data transfer at the appropriate service level.

The implementation of QoS enables real-time applications such as network TV and network music to use network bandwidth most effectively. Because it ensures that a certain level of assurance has sufficient network resources, it provides a service level similar to a private network for a shared network. It also provides a means of informing application resources of availability, allowing applications to modify requests when resources are limited or exhausted. The goal of introducing QoS technology in Windows XP systems is to establish a guaranteed transmission system for network communication.

From the above Microsoft's explanation of QoS we can see that by modifying 20% of QoS in the Group Policy Editor to 0%, it does not achieve the goal of optimizing network performance. The modified 20% parameter in Group Policy refers to the maximum amount of bandwidth that can be used when the QoS API program is used to access the network, and if we set it to 0%, it means that applications written using the QoS API have to compete with other applications for limited bandwidth. The likely consequence is that data that requires priority communication is not given priority. From this point of view, changing QoS 20% to 0% is not a good thing, but it can also make some real-time network applications not use network bandwidth effectively. So this so-called optimization technique can be said to be a misleading.