What are the software components in the communication path between the agent and the Notification Server?

The Altiris Agent communicates to its managing Notification Server through a set of interfaces available via http/https on the NS. But given the number of computers that a NS can manage at any given time the concurrency aspects of this communication stack are not always easy to understand.

Here is a diagram I created whilst troubleshooting some IIS communication error, with details of the software components and configuration items that are part of the communication stack on the server [click on the image to enlarge]: