Edit: See this post for a working practical config with a router that uses these settings.
Update 2013-05-30: The solution described at the end of this post is applicable to Windows 7 Professional and other non-‘home’ editions. Windows 7 Home Editions do not appear to have group policy editor (gpedit.msc) installed as standard.
I spent a fair amount of time trying to get to the bottom of this and so thought I would share my experiences, and partial successes. This post describes the issues I had trying to stop Crashplan’s upload traffic slowing down everything else on the network while utilising the available bandwidth for very large uploads. It talks about Differentiated Services Code Point or DSCP, QoS, Netmon packet monitor, Group Policy settings, and various unsuccessful fixes to the problem of Crashplans DSCP setting having no apparent effect either due to a bug or limitations of Windows 7. This post doesn’t discuss router configuration (to be part of a separate post), just Crashplan and DSCP on Windows 7.