Major IDMs connecting to the agent are largely anonymous. However, if a connection between an IDM and the agent is interrupted for any reason and IDM is able to reestablish its connection the agent needs to know that it is the same IDM instance and not a brand new one so it can continue sending any buffered responses to that same IDM. A GUID generated and cached by each IDM and passed to the agent (as a header?) during the initial connection can be used by the agent to implement the behavior described above.