There are default assumptions made according to Cowbee SDN VPN services below,
1) When Cowbee SDN VPN is in active status, it shall disconnect automatically after 5 minutes if "idle (no traffic)" more than 5 minutes.
2) When Cowbee SDN VPN is in active status, it shall disconnect automatically after 30 minutes if "idle (no local internet data network)" more than 30 minutes.
3) At last and mostly happened that your local network is not stable which caused the Cowbee SDN network unstable.
4) There are behavior different among PPTP and L2TP VPN service where PPTP allows multiple logon with single tunnel session and L2TP allows single logon with multiple tunnel sessions. L2TP VPN user shall experience connection dropout when same logon attempt to login.