What is "Local Area Connection Status"

I just set up a password protected wireless router on Windows XP and now the "Local Area Connection Status" window is randomly popping up. Not sure what this window is. I never saw this window before I set up the router. I am also a little concerned because the last time it popped up it said Duration:10 mins, and 22,006 packets sent / 26,524 packets received but I had not been on it all day. Not sure what a "packet" is but I would think both numbers should be the same. I ran AVG and it says there is nothing wrong but I am worried there is something connecting to me even when I am not online. Any idea why the window is popping up and or why its showing any duration time when I have not been on it?