Please take a look at the following questions:

  • What is NSX?
  • What the heck is the difference to Nicira NVP or are they the same?
  • What are the technologies behind NSX and how does it work?

Is there any you cannot answer, yet? If so, I would like to direct your attention to two just great videos on Youtube which will clarify:

OpenStack Networking – Theory Session, Part 1

OpenStack Networking – Theory Session, Part 2

Watching this will be the best 1h 45min you have invested for a while!

Have fun!