Throwing this issue out there, maybe someone has experienced the same problems. Here's the basic info, obviously there are a lot of factors, but any help is appreciated.
We have a fully meshed 11 site MPLS network through our carrier, HQ has 9mb and each office has a T-1. Cisco equipment throughout, except Riverbed boxes in each office. Microsoft for servers and clients. Some services (DHCP, some Exchange for example) are centralized and users do map drives and access files back to HQ. No WINS, DNS in each site.
Problem: When an offices WAN link gets high utilization, all users in that office pretty much lockup, even if they are accessing resources that are local. I have done packet tracing as well as Netflow locally and haven't see anything that stands out. The server team tells me that all sites have DC's and are global catalog servers.
Again, advise would be greatly appreciated.