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Myth - XP reserves 20% of the bandwidth

May 2015

Microsoft Windows XP is one of the most popular operating systems and has a mechanism that sets aside and uses a percentage of the bandwidth for QoS requests. This technology enables special priority requests from software applications shared on the network to be carried out. In normal conditions, "myths and legends" have it that this 20% of network bandwidth is unreservedly available for all shared applications. The bandwith is then shared when applications make a request. This is done to ease network congestion. It is possible for the administrator to change the percentage of reserved bandwidth by using "gpedit.msc" to change the system policies.

Windows XP reserves 20% of the bandwidth



Myth


Microsoft Windows XP reserves 20% of your bandwidth for its own purposes.

Reality


False, although there are many technical reports supporting the fact that XP is stealing bandwidth.

Explanations


Windows XP makes an optimized use of the bandwidth; 100% of the bandwidth is available almost all the time for shared applications, unless an application specifically requests priority over the bandwidth through the QoS. By default 20% of the bandwidth is allocated for these special requests, but under normal circumstances this reserved bandwidth can be freely used by any shared application or data flow.

QoS:

The Network Quality of Service (Qos) regroups the various mechanisms and techniques used to prioritise one type of dataflow or a program running on a network. This is done when there is network congestion.

However you can modify the % of reserved bandwidth, just follow the steps below:

Type GPedit.msc in the Run console.

Expand the local computer policy, administrative templates and the Network branch.

Select the QoS Packet Scheduler and in the right window you will get the reservable bandwidth settings.



Enable this option and then modify the % of bandwidth. You can reset it from 20% to 0%, though this will not increase your connection.
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Published by netty5. - Latest update by Virginia Parsons
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