How does ConnectPro identify a client.

From the documentation:

2 The proxy server establishes a session with the host on behalf of the Client and keeps track of the session information. This is called the proxy-host connection.

How is this tracked?

For example, if there is a connection interruption, how does Connect Pro identify that Client-X should be resumed to Session-Y on the host?

What happens if that reconnecting Client changes IP?

Thanks