We have set up an MPLS with our telco. Main office is in Idaho, remote branch is in New Mexico. When we try to copy large files across the pipe, we get errors. If I've done an SSH session to the router in the remote office, I randomly lose my connection. We use UltraVNC as a support tool to do remote sessions with our users in New Mexico, and it will frequently lose connection and we have to reconnect. If you do a MSTSC remote desktop session out to a server in New Mexico, it will have frequent hiccups where it has lost the connection and has to re-establish it.
When we opened a ticket with the telco to try and figure out why we're having these problems they ran some tests overnight and just sent us back results saying: "Tested clean to the NIU and the CSU." Which is great, but doesn't really help us address the problem. The only thing I can see on the routers when I do a 'sh int' on the routers is that they have a large number of total output drops. This would generally indicate congestion on the interface, but there just isn't that much traffic flowing across. I've used the SolarWinds Netflow Analyzer and I don't really see any more than about 75Kb/s worth of bandwidth being used.
The question I'd have then is that the router is connected into my network at 100Mbps, and the serial link is 1.5Mbps. Am I just overwhelming the interface by squeezing from 100Mbps to 1.5Mbps from one interface to the other? Anyone have any ideas of why I'm having these problems?