Review on NeSSi2 by Brett Kolpack

NeSSi allows you to simulate both wired and wireless networks. It also lets you configure devices and run them in your environment. It's free software so there are no limitations, but for large scale environments I would recommend using licensed versions with more resources. The documentation is lacking. There isn't much help online, and most of the tutorials that do exist are out of date. You will have to learn how to use the tool by trial and error. It took me several hours to figure this out. Once I did, however, it became very easy to use. We were able to test protocols and configurations to ensure we had everything correctly set up.