Sent a keepalive on the IPSec SA

Hi,

My Cisco Client VPN is 4.6.03. On the log I see a lot of messages like this:

I have seen that when I left my computer for a few minutes, the connection is over and there is the following message on the screen:

"Secure VPN connection terminated by Peer. Reason 433: (Reason not specified by Peer)"

I have connected from other office to the same Cisco router, and on that message isn't on the log, what I see at this office is the message "Sent a ping on the Public IPSec SA".

Does anyone tell me some about "Sent a keepalive on the IPSec SA".

Thanks,

M.G.