VPN Disconnects after 3min of activity

I'm having a hard time trying to figure out why my vpn connection is
being terminated after exactly 3 mins with activity. I will vpn into
my 2003 server and connect then fire up my remote desktop and after 3
mins the remote desktop stops and at about 4 mins the vpn connection
finally drops off. I can reconnect and it works again for 3 min. In
the event log its says disconnected by remote user. This happens on
sever computers. If I connect through the lan side with RDP it never
drops. I can't figure out what is causing this, router, modem or
server?? If my ISP was blocking vpn connections I wouldn't be able to
connect. Any ideas? Thanks

It could be the MTU issue. This search result may help,

VPN connection is disconnected after several minutes VPN connection is disconnected after several minutes. We have been seeing more and more cases like this one. We don't really know the causes, ...
www.chicagotech.net/VPN/vpn3minutes.htm


Bob Lin, MS-MVP, MCSE & CNE
Networking, Internet, Routing, VPN Troubleshooting on http://www.ChicagoTech.net
How to Setup Windows, Network, VPN & Remote Access on http://www.HowToNetworking.com
"Barkster" <(E-Mail Removed)> wrote in message news:(E-Mail Removed) ups.com...
I'm having a hard time trying to figure out why my vpn connection is
being terminated after exactly 3 mins with activity. I will vpn into
my 2003 server and connect then fire up my remote desktop and after 3
mins the remote desktop stops and at about 4 mins the vpn connection
finally drops off. I can reconnect and it works again for 3 min. In
the event log its says disconnected by remote user. This happens on
sever computers. If I connect through the lan side with RDP it never
drops. I can't figure out what is causing this, router, modem or
server?? If my ISP was blocking vpn connections I wouldn't be able to
connect. Any ideas? Thanks