I have started digging around a bit starting with ServicePoint and SoapRequest. However it looks like there is quite some way to go until I'd come to the point where the threads actually are being put to sleep. I suspect it would happen somewhere in the HTTPRequest class. you might be able to shortcut this as to where in the .NET space the dispatching (and supposedly putting to sleep) is likely to occur. Unfortunately there is this thing called work getting in the way. Cheers Stephan