The Networked Resource Discovery Project of Colorado has investigated a number of issues concerned with allowing users of the Internet to discover resources of interest in large administratively decentralized environments, including resources such as documents, network services, and people. Implicit in these projects is the assumption that the Internet will continue to grow and evolve as a medium for supporting wide area distributed applications. In response to a number of well publicized problems many sites have installed mechanisms to limit their exposure to security intrusions. While these measures are preferable to the damage that could occur from security violations, taken to extremes they could limit the capability of the Internet. To understand the evolution of this situation, the researchers propose to carry out a longitudinal measurement study of changes in service-level reachability in the global TCP/IP Internet. The data they gather will uncover changes in how sites resolve the problem of supporting open network usage while ensuring reasonable security.
