Centrifugal defeats Centripetal (TCP v X.25)
ARPA's networking endeavors, like those at RAND previously, were totally at odds with the ethos of the telephone industry. The reason for this conflict extended back to the industry's very origins. In 1877 Alexander Graham Bell was granted a second patent for his telephone and formed the Bell Telephone Company. For a brief period, only Bell Telephone and its licensees could legally operate telephone systems in the United States. Then, when his patent expired at the end of 1893, a glut of competitors rushed into the market. Between 1894 and 1904, over six thousand independent telephone companies went into business in the country. This had two effects. First, it dramatically accelerated the proliferation of telephone systems across the United States. Second, it resulted in a chaotic mess of incompatible telephone networks. Telephone subscribers might indeed find themselves newly connected, but they were also unable to use their telephones to communicate with people who did not happen to be on the same system they subscribed to. In the 1908 annual report of AT&T (as Bell was known from 1899 when it came under the ownership of its subsidiary, AT&T), the president of the company, Theodore Vail, warned that only through universal and consistent service could reliable telephony be assured. The solution, AT&T argued, was monopoly. As its 1908 marketing slogan put it: "one policy, one system, universal service." Vail's argument prevailed and in 1913 AT&T became a government-sanctioned monopoly under the regulation of the Federal Communications Commission (FCC).
AT&T's control over the United States' telecommunications network was so absolute that, until the late 1960s, homeowners in the United States were even forbidden from modifying their telephone sets in any way.
From this point on, AT&T's control over the United States' telecommunications network was so absolute that, until the late 1960s, homeowners in the United States were even forbidden from modifying their telephone sets in any way. While Bell Labs, a research unit within AT&T, was a hive of innovation, the company had no strategic interest in transforming its network. AT&T was firmly wedded to the orthodoxies of central control and knew with the benefit of long experience that the circuit switching of telephone calls, the technology that Alexander Graham Bell had patented in the late 1870s, worked as it was. Thus Paul Baran had been rebuffed in the mid 1960s when he approached AT&T with the opportunity to use the packet-switched networking concept he had developed at RAND. Even so, in 1968 ARPA had anticipated that the successful demonstration of four functioning nodes in a data network would convince a telephone company of the merits of digital networking. The original planning document for the ARPANET project included the optimistic objective of transferring the technology so that a utility could provide "digital message transmission as a tariffed service." Yet even in 1975, after proof of concept and extensive testing of the packet-switched distributed network concept had been successfully conducted at the taxpayers' expense in the form of the ARPANET, AT&T refused to pursue the Internet idea.
Shortly thereafter, in the mid to late 1970s, telecommunications companies in Europe, Canada, Japan and the US did begin to appreciate that the potential of digital packet-switched networks should no longer be overlooked. While some public data networks had been established in the late 1960s and early 1970s, such as the Broadband Exchange Service in Canada from 1969, many telephone companies found the digital network revolution challenging. This was not least because they had been beaten to this conclusion by the computer manufacturers. While the ARPANET used open, non-proprietary standards to which any manufacturer's devices could connect, the commercial computer manufacturers began to offer proprietary equipment and networks that were incompatible with machines supplied by their competitors. Thus telephone companies would not be able to choose suppliers on the basis of competitive prices if they built a network using proprietary equipment from IBM, Digital Equipment Corporation (DEC) or some other supplier's technology. Thus, even as they became interested in data networks, the telephone carriers grew concerned that they might become in thrall to the equipment manufacturers.
The solution, the telecommunications giants realized, was to create an open standards network, the equipment for which could be produced by a plurality of suppliers, but over which they could retain the strict central control that they had always exercised over the traditional telephone and telegraph networks. Though they were keen to avoid monopolies in networking equipment, many of the telecommunications carriers were monopolies themselves. Outside the United States, telecommunications services were often offered either by regulated monopolies along the AT&T model or by the so-called "PPTs" (governmental ministries of posts, telegraph and telephone) or by nationalized companies. Within the US, as ARPA and the networking researchers it funded were veering off in the direction of multiple networks, decentralized control and open standards, AT&T remained fixed to the Vailian ideas that had helped to make it one of the largest corporations in the world. In the late 1970s, J.C.R. Licklider had cautioned that different networks would be unable to communicate with one another unless common standardized protocols were introduced. This is indeed what began to happen.
Between the mid 1970s and the late 1980s, a pivotal period in the expansion of networking to the public, ARPA and its allies fought a standards war against the telecommunications industry. Representing the interests of the telephone industry was the Consultative Committee on International Telegraphy and Telephony (CCITT), a body of the International Telecommunications Union (ITU). Within the CCITT a group began working on the question of standards in 1975. The resulting protocol, X.25, was adopted by the CCITT in September the following year. Despite their dawning awareness of data networks as an emerging market, the telephone companies had not fully made the leap to the concept of distributed networking that lay at the heart of Baran's work at RAND in the early 1960s. Nor had the telephone companies embraced ARPA's approach towards diversity. Foremost among Baran's considerations had been the need to provide a robust communications infrastructure using unreliable, redundant equipment. The telephone companies took the view that digital networks, like the analogue networks for telephone and telegraph before them, could only offer reliable service if every aspect of the network were controlled by the operating company. The imperative for ARPA had been to enable "a very broad class of interactions" between a diverse array of incompatible computers and networks that served different purposes. Thus where TCP/IP enabled diversity, X. 25 required consistency and conformity.
In contrast, TCP/IP, like the French network Cyclades, used "datagram" packets. Datagrams are simple, elemental packets that can be combined as needed by host computers to scale up or down the level of complexity in their communications. X.25, however, was built to provide consistently high-quality communication in all cases—whether necessary or not—which made it inappropriate for many uses. This distinction between TCP/IP, which used datagrams, and X.25, which rejected them in favor of consistent and rigidly controlled communications, was an ideological division45 between two generations of engineers, centripetal on one hand and centrifugal on the other, as much as it was technical. Vint Cerf, one of the chief architects of TCP, recalls that he had offered TCP/IP to the CCITT but had been rebuffed because the protocol had come from the Department of Defense, and because "they thought they could not 'sell' datagrams."
TCP/IP did not only accommodate different devices, but accommodated many different types of networks too. TCP/IP could be used inside a network, or to connect many networks, or both. Not so for the telephone companies. Their interest was in national public data networks. The diverse array of networks of varying sizes, architectures and purposes that TCP/IP could support, and which the Internet eventually became, was beyond their view. According to Cerf, TCP/IP "eventually won out because it was so general." Ultimately, homogenous X.25, the expression of the centripetal bent of the telephone industry, was defeated by TCP/IP, the open, diverse and untidy offering of the research community. As TCP/IP spread across the globe, communications began to take on the centrifugal character that had previously been the preserve of participants on the ARPANET. Moreover, new opportunities beckoned for underground, amorphous communities drawn together by common interest rather than proximity. The growth spurt that the early Internet enjoyed in the late 1980s was partly due to the ability of TCP/IP to work at both the macro and micro levels. This proved to be enormously fortuitous for the development of the Internet.