Layers of Management Interactions

In all networked systems, communications are structured into layers. This includes management communications. Before diving into the patterns of communication exchanges between managers and agents, let’s talk briefly about how management communications are generally structured into layers—that is, the different roles and functions that you will find in layers of a management protocol stack.

The topmost layer of a communications stack is generally the application layer, which provides communication applications with services and communication primitives that they can use to directly communicate with each other. (“Primitives” refers to basic communication operations.) Examples of communication applications are e-mail (an associated protocol is the Simple Mail Transfer Protocol, SMTP) or file transfer (an example of a protocol is the File Transfer Protocol, FTP). Application-layer protocols are generally defined without concern for the physical characteristics of the underlying network (for example, wireless or Ethernet) or how to route the data across multiple intermediate hops. Lower layers in the communications stack address those aspects.