Machines with default network access are unable to connect to internet resources that are not on the University network. A gateway connecting the University network to the internet effectively stops traffic between machines on campus and machines in the external world. Machines on the University network with Proxy access connect to a server that connects to internet locations on behalf of each user.
Full access allows a machine to connect to the internet without having to use a proxy.
This opens the machine up to the internet so that anyone who knows it is there, and who has appropriate rights is able to connect. WWW servers that provide information to the public beyond the confines of the University network need full access. WWW servers intended for University access only can have Proxy access, or the default, no access. If information flows between a machine on the University network and a machine outside of this network, a cost is incurred. This cost is directly related to the amount of information transferred, and is modified according to the time of day, and the direction of flow.