When folks are working remotely, it is usually over a VPN tunnel. Trying to debug these connections can be difficult because there are so many carriers involved in passing the traffic along the Internet.
This is where you can use the “Link Troubleshooting” mode of PathSolutions Call Simulator. This type of test will identify all of the routers along the way, and also show you the latency, jitter, and packet loss that occurs to each router, so you will know which carrier is causing the problem, and what type of problem it is.