The United States National Science Foundation (NSF)
is making a transition away from supporting
Internet backbone services for the general
research and education community. One component
of these services, the NSFNET backbone, was
dismantled as of the end of April 1995. To
facilitate a smooth transition to a multi-provider
environment, and hopefully forestall the
potential for network partitioning in the
process, the NSF is sponsoring several official
Network Access Points (NAPs) and providing regional
service providers with incentives to connect to
all three points.
NAPs are envisioned to provide a neutral, AUP-free meeting point for network service providers to exchange routing and traffic. The three NSF-sponsored priority NAPs are:
NSF also sponsors a non-priority NAP, in Washington, DC, operated by Metropolitan Fiber Systems.
The Sprint NAP was operational as of November 1994, but the other NAPs were not yet ready until mid-1995, mainly because Sprint was the only NAP who did not try to start off with switched ATM technology, but rather begin with an FDDI implementation. In addition, NSF is sponsoring a very high speed backbone service (vBNS), based on ATM technology, to support meritorious research requiring high bandwidth network resources. The vBNS represents a testbed for the emerging broadband Internet service infrastructure in which all parts of the network will be experimented with: switches, protocols, software, etc., as well as applications. It will be a unique resource for network and application researchers nationwide to explore performance issues with the new technologies (e.g., how host systems and interfaces interact with ATM components of the wide area network) [1,2].
As the NSFNET era comes to a close, we will no longer be able to rely on what was the only set of publicly available statistics for a large national U.S. backbone. The transition to the new NSFNET program, with commercially operated services providing both regional service as well as cross-service provider switching points (NAPs), will render statistics collection a much more difficult task. There are several dimensions of the problem, each with a cost-benefit tradeoff. We examine them in turn.