The Evolving National Information Network
There are a variety of networks in operation throughout the nation today. Rather than attempting an exhaustive description, those networks most relevant to the library community will be described briefly.
Development of the packet switched network infrastructure has been actively underway since the 1960’s. The first substantial implementation was the ARPANet, developed with support from the Department of Defense (DOD) Advanced Research Projects Agency (ARPA). The ARPANet technology led to the development of the TCP/IP protocol suite which is now the defacto standard for the higher education and research community. Access to the ARPANet was initially restricted to government funded researchers, but by the end of its life had in fact been substantially broadened. The ARPANet was managed by the Defense Communication Agency, with operations at Bolt, Baranek, and Newman (BB&N) and a Network Information Center at SRI. It was dismantled in 1989; replaced by NSFNET for non-DOD use and by MILNET for DOD activities.
CSNET was established in 1981 with initial grant funding from the National Science Foundation, and has been self-supporting since 1985. It is based on the TCP/IP protocol suite, and has been connected to the ARPANet from its inception. CSNET was developed to support the university computer science community and has been open to research and development efforts in both the higher education and industrial communities. CSNET uses both switched and leased circuits, as well as the X.25 protocol. CSNET was originally operated by the University Corporation for Atmospheric Research (UCAR) with network operation, coordination, and an information center at BB&N. CSNET is now merged with BITNET to form the Corporation for Research and Education Networking (CREN).
BITNET was initiated as an informal experiment in information exchange between the City University of New York and Yale University using IBM’s Network Job Entry (NJE) protocol. It has since grown to become an international network serving thousands of hosts worldwide. BITNET has extensive gateways to other networks, and is perhaps the most ubiquitously accessible network in the world. BITNET has been self-supporting since its inception and has been used primarily in the higher education community. It is now using TCP/IP for much of its data transport capability, but does not directly support the ARPA protocols. BITNET is operated by CREN with a Network Information Center operated by EDUCOM.
NSFNET was established in 1987 by the National Science Foundation to provide connectivity among the six recently established national supercomputing centers and the networks emanating from those centers. It uses the TCP/IP protocols, and was from the beginning transparently connected to ARPANet and CSNET. NSFNET is open to research, education, and development activities in the higher education and industrial communities. NSFNET started using 56 kilobit leased lines, non-commercial Internet Protocol(IP) routers and the existing ARPANet infrastructure. Traffic quickly outgrew the capacity of those facilities, and in 1988 the National Science Foundation awarded a 5 year cooperative agreement for construction and operation of a new backbone to MERIT. MERIT is a not-for-profit state networking corporation of Michigan universities with operations in Ann Arbor, Michigan. MERIT established a partnership with IBM and MCI for computing technology and communications facilities, respectively.
During the same period, NSF also funded a number of regional networks that, along with the connections to the supercomputing centers, were interconnected by the backbone. Since its inception, traffic on the backbone has grown at a compounded rate of more than 1O% per month. The NSFNET backbone was originally implemented using T1 (1.5 megabit per second) leased lines, and has now been upgraded to T3 (45 megabit per second) leased lines. NSFNET interconnects more than 1000 universities and colleges, and through links to the broader TCP/IP-based internet provides global access to thousands of networks and hosts. It now also provides ISO-based transport capability.
A large number of networks have been developed to support library activities. Many of those networks are better described as organizational rather than technological artifacts. Rather than attempting to characterize the many regional networks serving particular library groupings, those networking initiatives that provide broad, national access to large utilities will be described. The first is operated by the Online Computer Library Center (OCLC) and provides nationwide access to the bibliographic database maintained by OCLC in Columbus, Ohio. The second is operated by the Research Libraries Group (RLG) and provides nationwide access to its owner institutions to a large bibliographic database in Palo Alto, California. While both networks were created on the basis of proprietary protocols, they have agreed to use OSI protocols and have gateways to the TCP/IP internet for limited sets of services. Both of these systems, worked with the Library of Congress and other large bibliographic utilities, on the Linked Systems Project. The goal of this project was to allow the bibliographic assets of these systems to be shared and accessed in a distributed fashion. This project resulted in the creation of the Information Retrieval Protocol, Z39.50. This protocol allows users to search and retrieve bibliographic items from other systems without the user having to understand the command language, bibliographic structure, or system specific characteristics of the remote system. This protocol has now been adopted as a national standard by the National Information Standards Organization (NISO) and the American National Standards Institute (ANSI).