When probe sends data to app server is communication started from probe or app server?

 

I have a  question about the protocol workings of a probe.

 

When data is sent from the probe to the app server  is  communication session initiated from the probe or the app server?

 

I know when you start the a job the app server sends the command down to the probe.  I am just not sure if a communication session remains open or a new commutation session starts when the probe has data to send to the app server