The vBNS (very high-speed Backbone Network Service) is a network that interconnects a number of supercomputer centers in the United States and is reserved for science applications requiring the massive computing that supercomputers can provide. Scientists at the supercomputer centers and other locations apply for time on the supercomputers and use of the vBNS by describing their projects to a committee that apportions computer time and vBNS resources. The vBNS and the supercomputer centers were initiated and are maintained by the National Science Foundation (NSF).
The vBNS began operation in April, 1995, as the successor to the NSFNet. The NSFNet itself succeeded DARPANET, the original Internet network. The vBNS is the scientific portion of the Internet that NSF continues to fund. The physical infrastructure for the original Internet is now owned and maintained by the national commercial backbone companies in the United States and worldwide.
Currently, MCI provides the backbone infrastructure for the vBNS under contract from the National Science Foundation. The backbone consists mainly of interconnected Optical Carrier levels (OCx) lines (operating at 155 Mbps or higher). The vBNS provides connections to the four national network access points (NAPs). The vBNS infrastructure itself is not shared with commercial companies and ordinary users.
As part of the evolution toward a commercially self-sustained Internet, the National Science Foundation continues to operate the routing arbiter, a service that the NAPs and other routers use to route and reroute packets and optimize traffic flow on the Internet. The routing arbiter service is managed by Merit under a contract from the NSF that expires in July, 1999.
The vBNS has recently become part of the infrastructure of Internet2. A new NFS-funded initiative is developing an advanced network infrastructure referred to as the National Technology Grid.