Slow VPN connection?
 

In our domain network, we have a vpn server as well as vpn clients who work from home. Also we alternative direct DSL connection to external network - used sometimes for special purpose connection to the internet.
Now the connection to a different site (branch office) via the usual wired LAN has fast and normal speed. But the problem is that when a user wants to connect to the same site/office via VPN or DSL the connection speed reduces drastically - slowing file downloads and stuffs (up to 20 times slower!)
Anyone gone this kind of problem before, or have solution to this please?

Check the VPN server carefully, for instance monitor the processor usage. Maybe it gets overcrowded sometimes?