Strigo is a fully managed solution that runs in the browser (see here for supported browsers). All that's required is a browser and an internet connection (and making sure that port 443 is opened). Even the labs are in the browser. How cool is that?
To make sure everything works, you can ask your organization's firewall admin to white-list the following domains:
If you don't need to use audio/video, you don't have to white-list *.opentok.com and *.tokbox.com
If you don't intend to use the lab's editor, you don't have to white-list *.firebase.com and *.firebaseio.com