NFV Management and Orchestration: relationships between components

As I’ve been investigating a new trend in networking, Network Function Virtualization or NFV, I’ve noticed that far and away the vast majority of writers recycle some version of the same architecture diagram. Here’s one:

NFV Management and Orchestration

NFV Management and Orchestration

This and similar diagrams lack important relationship information that I have found is spread thin in words over many texts. In the NFV MANO specification, however, I found a sequence diagram that highlights the relationships between a few of the major management and orchestration components:

VNF InstantiationThis screenshot from the PDF was the best I could find for clarity. It’s a pinch easier to read in the specification itself.

One of the important interactions that this diagram showed me was the fact that NFV allocation comes back from the VNF Manager to the Orchestrator. The Orchestrator then calls into the VIM for the real allocation. I hadn’t seen this prior.