I am more interested in getting an "Available Bandwidth" estimator. Due to this available bandwidth, I am interested in congestion window. As whenever congestion window goes to half it means the data rate has gone to its upper limit. I want to use this particular property of congestion window to calculate bandwidth. Any idea how can one do bandwidth measurement based on this? Thanks a lot, Ghulam On Wed, Oct 5, 2011 at 7:18 PM, Leigh Porter <leigh.porter@ukbroadband.com>wrote:

I used a passive TCP RTT calculator and TCP re-trans monitor to guess the conditions to a host or group of hosts with some success. I the. Derived the network "weather" from this and it worked pretty well to dynamically tune DPI box policing for wireless networks.

It also makes cool graphs. Especially if you add other parameters and do it all in various colours.

-- Leigh

On 5 Oct 2011, at 07:41, "Murtaza" <leothelion.murtaza@gmail.com> wrote:

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Hi everyone, I want to do passive available bandwidth measurement. I was just wandering what tools/techniques people are generally using these days. And is it a good idea to use congestion window as parameter. Ghulam

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Any idea how can one do bandwidth measurement based on this?

vern paxson did extensive work in this area. van jacobson too.

For more recent work, see the papers of Constantine Dovrolis. (Likely others, too, but that's the work that comes immediately to mind.) Vern