All network devices buffer data on the way to clients. In the case of an AP the principal buffers are in the driver's read and transmit buffers and the txqueue
The size of the txqueue can be seen with ifconfig. Wired device buffering can often be seen with the ethtool -g [the interface] but that is not implemented everywhere wireless device buffering is more complex (by far!) as not only do you have buffers on tx, you also have retries and aggregation to account for. Not a lot of which is user visible, but can be seen in the source code. If you are asking specifically how to see how full the buffers are, there is presently no good way to do that. It is however, possible to empirically measure the buffer size by flooding the device with network traffic, then measuring the delay of a given packet end-to-end. Note that in the wireless case, forcing the wireless interface to a low transmit rate will generally show bufferbloat in action. You can force low transmit rates by adding distance between the AP and client or via software On Thu, Sep 22, 2011 at 10:11 PM, 马进 <ji...@kaist.ac.kr> wrote: > Hi all, > > How could we know whether the AP is buffering data to its associated > clients/STAs? And how to know the size of the buffered data? > > Thanks. > Jin > > > > _______________________________________________ > openwrt-devel mailing list > openwrt-devel@lists.openwrt.org > https://lists.openwrt.org/mailman/listinfo/openwrt-devel > > -- Dave Täht SKYPE: davetaht US Tel: 1-239-829-5608 http://www.bufferbloat.net _______________________________________________ openwrt-devel mailing list openwrt-devel@lists.openwrt.org https://lists.openwrt.org/mailman/listinfo/openwrt-devel
