Hello, we have a VPN concentrator at our side and then various VPN connections with Cisco's 871 routers. Once the costumer stops for lunch or something similar ( a lapse of time ) The VPN tunnel goes down and we have to do a ping to their network to bring the tunnel back. We tried everything and there's no apparent solution to this problem! We want the VPN always up no exception ! Can you say why and if you know, how to solve this issue ?