RPCNET

Figura 1 — RPCNET connections across Italy: Turin, Milan, Pisa, Rome/Frascati, Palermo.

RPCNET

Pioneering Computer Networking in Italy (1970–1985)

The origins of RPCNET can be traced back to the early 1970s, when CNUCE, (Centro Nazionale Universitario di Calcolo Elettronico) the University National Center for Computing in Pisa, established a close collaboration with the IBM Scientific Center located just across the street from its headquarters.

As part of this partnership, four researchers from Pisa—Renato Matteucci and myself from CNUCE, together with Paolo Franchi and Alessandro Fusi from IBM—spent the years 1973 and 1974 at the IBM Scientific Center in Cambridge, Massachusetts. Our objective was ambitious: to position Italy at the forefront of the emerging field of computer networking.

The experience proved invaluable. We worked alongside researchers from IBM laboratories and leading American institutions that were shaping the future of data communications. Among the most stimulating interactions were those with the engineers of the IBM Watson Research Center, then developing IBM’s Systems Network Architecture (SNA), with researchers at Bolt Beranek and Newman (BBN), the company responsible for ARPANET, and with the designers of the MERIT network at the University of Michigan.

These encounters exposed us to some of the most advanced networking ideas of the time and laid the foundations for what would become the first Italian computer network.

In June 1974, the REEL (Rete Elaboratori Elettronici) project was officially launched through a collaboration involving CNEN (Bologna), CNUCE (Pisa), CSATA (Bari), the IBM Scientific Center in Pisa, and the computing centers of the Universities of Padua and Turin. Its goal was to design and build a national computer network interconnecting the computing resources of these institutions.

The project soon became known as RPCNET (REEL Project Computer Network), marking the birth of Italy’s first large-scale computer network.

To give national visibility to the REEL project, CNUCE and the IBM Scientific Center in Pisa organized a press conference in Milan on 21 October 1976 for Italian science journalists. The following day, a workshop was held in Venice to present the RPCNET architecture and protocols. The event was attended by leading representatives of the Italian scientific community and by major ICT companies of the time. For the first time, a national computer network, entirely designed and implemented in Italy, was presented to a broad public: a system capable of competing with ARPANET and with other advanced networks then under development.

By the end of 1976, the RPCNET software was already running on the IBM processors used by the REEL project partners. The IBM System/7 minicomputer, acting as a front-end processor, also served as a terminal concentrator, with functions similar to those of the ARPANET TIP. Between 1976 and 1978, the RPCNET software was tested in several partner computing centers, made more reliable, and enriched with tools for measuring traffic between network nodes and collecting statistical data.

Technical Analysis: The RPCNET Architecture

RPCNET was not merely an experiment in connecting computers; it was a sophisticated networking system that anticipated many concepts that would later become standard in modern computer networks.

The architecture was organized into two main functional layers. The lower layer provided communication services, while the upper layer offered interface services that enabled applications to access network resources.

From the user's perspective, RPCNET offered a remarkably advanced set of services for its time. Researchers could transfer files between remote computers, access distant operating systems, and exchange electronic messages. To facilitate the development of new applications, the RPCNET team also created RNAM (REEL Network Access Method), a collection of software tools and programming interfaces that allowed users to build their own networked applications.

At the communication level, RPCNET managed the transmission of data across physical links connecting adjacent network nodes. Its software was responsible for packet forwarding, route selection, and network reconfiguration in response to hardware or software failures. These capabilities ensured that communications could continue even when parts of the network became unavailable.

The interface layer provided logical communication channels between applications running on different computers. Among its most innovative features were flow control mechanisms, segmentation and reassembly of data blocks, error recovery procedures, and dialogue management supporting both half-duplex and full-duplex communication.

Looking back, it is striking how several of these functions anticipated concepts that would later appear in the OSI Reference Model. Even more remarkable was RPCNET's support for a connectionless communication service at the application level. This service, used primarily for electronic messaging, embodied ideas that would reappear years later in Internet protocols such as UDP and in modern e-mail systems.

RPCNET therefore represented not only a practical networking solution, but also a laboratory in which many of the principles of contemporary computer networking were explored and validated.

From Research Project to National Service (1978–1985)

In 1978, a decisive step was taken in the evolution of RPCNET. The General Commission for Information Technology of the National Research Council (CNR) adopted the network as a key component of its national scientific computing strategy.

This decision transformed RPCNET from an experimental research project into an operational infrastructure serving the Italian scientific community. It also gave concrete expression to a vision first articulated in 1970 by Alessandro Faedo, Rector of the University of Pisa, and Guido Torrigiani, Director of CNUCE, who had foreseen the importance of connecting distributed computing resources on a national scale.

Between 1978 and 1985, RPCNET connected approximately ten scientific computing centers distributed throughout Italy, from Palermo in the south to Milan in the north. At a time when networking was still largely confined to research laboratories, Italian scientists were already gaining practical experience with distributed computing services.

The network quickly demonstrated its value. Researchers increasingly relied on file transfer, remote access, and electronic messaging services. Traffic measurements collected during the period documented a steady growth in network utilization and confirmed the usefulness of the services offered.

The experience also revealed an important cultural transformation. Initially, many users viewed computing as an activity centered on a single machine. Over time, however, they came to appreciate the advantages of combining local computing resources with access to remote systems offering greater computational power and specialized services.

Beyond its technical achievements, RPCNET became a vehicle for the dissemination of knowledge and expertise. Advanced computing centers such as CNUCE shared technical skills, operational practices, and software resources with newer institutions, contributing to the development of a national community of network users and professionals.

The project also provided an opportunity to experiment with organizational models for distributed computing and to rationalize the allocation of software resources across participating centers. In this respect, RPCNET served not only as a communication infrastructure but also as a pioneering exercise in national-scale scientific collaboration.

RPCNET and IBM: From Experiment to Innovation

The expertise acquired during the design and implementation of RPCNET had consequences that extended well beyond the project itself.

Within IBM, the experience gained in Pisa contributed to the launch of the PISA project (Prototype for Interconnection of Series/1 Applications), a collaborative initiative involving the IBM Scientific Center in Pisa and the IBM Development Laboratory in Boca Raton, Florida.

The objective was to develop a new networking architecture based on IBM Series/1 minicomputers. Drawing upon concepts explored during the RPCNET project, the team designed a highly efficient network capable of automatic reconfiguration and resilient operation.

The resulting prototype was demonstrated using ten interconnected Series/1 systems serving twenty simultaneous users. During the demonstration, communication links between systems were intentionally modified while the network remained in operation. Despite these changes, users continued their activities without interruption, providing a compelling demonstration of the robustness and adaptability of the design.

Although technically successful, the prototype was not developed into a commercial product. IBM had already committed to a different strategic direction based on its Systems Network Architecture (SNA), which became the company's standard networking platform.

Yet the true legacy of RPCNET extends far beyond any specific technology.

RPCNET demonstrated that geographically distributed computing resources could be integrated into a coherent and efficient national infrastructure. It enabled researchers to exchange information, access remote systems, and collaborate across institutional boundaries at a time when such capabilities were still rare.

Perhaps most importantly, RPCNET helped create a networking culture within the Italian scientific community. Researchers, engineers, and system administrators gained practical experience with distributed computing and network services, developing the knowledge and confidence that would later facilitate the adoption of Internet technologies.

When Italy connected to the global Internet a few years later, the transition was not starting from scratch. The experience accumulated through RPCNET had already prepared a generation of researchers and institutions for the networking revolution that was about to unfold.

For this reason, RPCNET occupies a unique place in the history of Italian information technology. It was not simply the first Italian computer network; it was the foundation upon which Italy's future participation in the Internet age was built.

Historical Significance

RPCNET was the first large-scale computer network designed and implemented in Italy. Developed at a time when computer networking was still in its infancy, it demonstrated the feasibility of integrating geographically distributed computing resources and provided Italian researchers with early experience in network-based services.

Beyond its technical achievements, RPCNET fostered a culture of collaboration among universities, research institutions, and industry. The expertise gained through the project contributed significantly to the development of networking in Italy and helped prepare the scientific community for the transition to the Internet era.

Today, RPCNET stands as a pioneering achievement in the history of Italian information technology and an important milestone in the evolution of computer networking in Europe.

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