DSL keepalive
 

I have a number of machines in public, unattended sites, and need to be able to ssh/vnc into them for admin purposes.
The problem is that Linux (unlike Windows) only sends data when it's told to, and when it stops, the DSL router drops the connection, only reconnecting when an outgoing connection is attempted (connection to web page etc...)
I'm wondering what is the best route to go in setting up a keepalive type script. The connection takes a few seconds to come up, so pinging 10 times should be plenty, but the problem here is that currently my ISP (for some strange reason) is quashing all ICMP packets, which means no traces and no pings.
Any ideas?

My DSL switch has a keepalive option in the switch, rather than the any of the linux boxes connected to it. Would that work?

Cheers--
Charles