Given a multiple site Active Directory we occurence problems with slow link detection GPO's. We want to use slow link detection on laptops which connect are via coorperate WAN (MPLS 4-Mbit/s) to main site (with DC). The problem is, that the slow link detection is not working as expected, so there isn't a slow link recognized. The client machine is Windows 7, DC is Win Server 2008 R2.
The slow link detection is configured for computer and user via the policies:
Computer Configuration\Policies\Administrative Templates\System\Group Policy\Group Policy slow link detection User Configuration\Policies\Administrative Templates\System\Group Policy\Group Policy slow link detection
Both are activated and set to 15000kbps. This setting are activated on clients and work fine. But it seems bandwith calculation does something freaky.
In boot analyzes via xbootmgr / xperf I can see, that for the Computer GPO a slow link is detected with a 12618kbps (<15000kbps) so IsSlowLink is true -> everything fine.
But for the User GPO's the detected bandwith is 228711kbps. There is no slow link detected and for example "Folder Redirection" is processed.
I didn't find any reason for this huge difference, the network route doesn't change between Computer and User Policy processing. Is it possible that the NLA uses any cached content to determine the available bandwith? We have a riverbed Wan-Optimizer between the two locations, is it possible that it optimizes the NLA bandwith detection? Any ideas where to look how the returned bandwith was calculated?