> One hopes that FlightSize == cwnd. However, we introduced the > FlightSize notion in RFC2581 because this is not always the case. Some > stacks let cwnd be changed regardless of how much of the window is > actually used. So, as an example say cwnd grows to 50 segments, but > only 25 segments per RTT are being injected. In this case, upon a loss > if cwnd and ssthresh were simply cut in half there would be no change in > the load placed on the network. But, since everything is keyed off > FlightSize, it would be 30 / 2 or half of the imposed load. Really it > is trying to get at the fact that the load imposed needs to be cut in > half. 25 / 2 I'm on the crack again. allman