[JXTA discuss] check if Peer is alive without Monitoring?

Hello everyone,
is there a possibility to check whether a Peer is online (alive)  
without having monitoring enabled?

Can somone tell me how much overhead Monitoring actually causes?
If I want to have Monitoring Peers enabled, would this be the  
"EndPointMeter"?
And does this then mean that all the messages which are sent from one  
peer to the other?

So many questions.
Thanks,
udo.