What it is
Eduroam is a service that allows local users and visitors from participating organisations access to the network using passwords issued by their home institution, so visitors do not have to wait to be issued local passwords and local users do not need to register their machine. In Chemistry Eduroam access is available via either wired or wireless connections, although wireless is most popular.
How to use it
Detailed instructions for Cambridge users are at http://help.uis.cam.ac.uk/devices-networks-printing/network-services/wireless/eduroam. Once your machine is set up you don't need to change the settings to access Eduroam at other participating institutions.
Visitors from other institutions need to have collected an authentication token from their own institution to set up their access but it should work as described in the link above.
Technical details on what open ports are provided locally can currently be found at http://help.uis.cam.ac.uk/devices-networks-printing/network-services/wireless/eduroam.
What advantages does it have
There is no need to register - anyone from a participating institution can use it. Local users can then use the Chemistry VPN service from the Eduroam network to allow wireless access to Chemistry printers.