I have 2 VPNs from a remote call center.
The voice was on 1 VPN, and the data (terminal sessions) on the other.
The voice VPN, every 5 minutes was having traffic stop -- sometimes only 1 way (i.e. ping at remote office, was pinging through VPN fine while ping to that PC, from HQ would drop 20 packets. But sometimes traffic stopped both ways.
The data VPN was totally stable -- so we moved the voip box's to that VPN -- and suddenly the same stuff started happening there.
We have restarted all routing/VPN equipment -- and we have verified we are not exceeding the bandwidth on our T1's.