Hi Stef, Reffering to page < http://www.docum.org/stef.coene/qos/faq/cache/7.html > I found a para as follows, " CBQ is not always as accurate as it should be. See docum.org on the test page for some tests with bounded classes. The algorithm used by cbq is very "link sensitive". It calculates the link idle time and for that it needs the real link bandwidth, average packet size and some other parameters. But there calculations are not always accurate. So it's possible that you will get inaccurate results if you use CBQ to limit the traffic in a class. " Here Iam slightly confused with real link bandwidth, Can I understand that while creating CBQ we need interface bandwidth (ethtool, mii-diag) and and while assigning the classes real link bandwidth is required. An example will definately help me. Can you pls suggest a way to find real link bandwidth....? As ethtool and mii-diag will only get the interface bandwidth. Regards -Raghu