Hi Leo,
It just means that the security association is built but at the current time it is idle(not encrypting or decrypting packets). The other information you left out concerning the status is the ipsec peer addresses which shows in the output of "show crypto isakmp sa ". If the it shows both the src and destination it menas that your tunnel is active. 5 means the time since this tunnel is active.
HTH, Please rate if it does.
-amit singh
