Mininet
Mininet is a network emulator written in Python. With it you can create a test network consisting of many devices, for example inside your laptop. It's a lot more light-weight compared to emulating switches/routers in GSN3. Initially Mininet appears to be more about easily getting working network rather than tinkering with all the features of devices, but OpenFlow has a lot of nifty capabilities that Mininet makes it a lot easier to explore. Anyway I think it's great that there are free software tools to learn how to setup the network. Check out the link below, there are some assignments that are used at Stanford about how to create your own link state routing protocol. Cool!
It's easy to set up a network with many switches, routers and hosts. You can specify packet loss, queue size and delays on links.
They did some tests between ssh and mosh, to see how much better mush was when there were packet loss or delays.
You could deploy a setup similar to what you've tested inmininet, with real products. OpenFlow is used in both mininet and in the real products :)
Install the mininet VM and test it
There are many ways to install mininet. They provide a VM that you can boot or you can install it in your OS, but it requires root access.
They got a walkthrough that is quite a nice intro to how to set things up mininet.
A note when using the VM image: If you're already running Linux, for example I run Ubuntu on my machine all I had to do was to "ssh -X mininet@ip-to-vm" to be able to run wireshark in the vm. That's a capital X.
SDN - software defined networking
Some sources of information:
http://mininet.org/ - The network emulator
https://github.com/mininet/mininet/wiki/Documentation - On the github there are assignments that you can use to learn more about mininet.
https://www.coursera.org/course/sdn - On Coursera there is a free introduction course to SDN starting May 27! I'm joining it, are you?
http://www.opennetsummit.org/archives-april2013/ Free presentations about SDN inside.
http://tech.slashdot.org/story/13/04/29/2324200/inventor-of-openflow-sdn-admits-most-sdn-today-is-hype SDN is just a hype?