I have an Enhanced Easy VPN server running on a 2801 router at my corporate office. I am using 851W routers in the field to connect with Easy VPN remote. This is working great from three locations with cable modems, but when i place an 851W at any of my Bellsouth DSL sites the VPN tunnel establishes connection and stays up for 2-4 minutes and then I lose connectivity. The VPN light is on on the router at the branch office and it shows as up from the SDM. And then every hour on the hour for 1 minute the tunnel comes up. If i ping -t the ip of the remote router from the corporate office with it is up for that 1 minute it will stay up as long as i keep pinging it. It was up for 12 hours last night and when i ended the ping it was down in just a few minutes. I am running 12.4 on the 851s. The funny thing is that i can take this same router with the same config and put it at a cable modem site and the tunnel never fails.