The Data Center Series, Second Intermezzo: Making History

I’m insanely curious, people are usually flabbergasted because, I do not go much on holidays, I work, and I study. What gives me joy the most is learning new stuff either by interacting with very smart people or by delving into research from all kinds of sources. Given I do study for the pure pleasure of knowledge, I do like a pinch of serendipity, hence this series will be most surely distributed here and there by what I like to call Intermezzos that while off the main topic, I hope they will give some more depth and hopefully amusement. While doing my research I came across this video created by Barrett Lyon / The Opte Project and it is an artistic representation of the evolution of the Internet:

I was thinking about my next article in this “Data Center Series” where I wanted to explain the main differences between DCs for cloud applications and most recent “AI ones” for training of Large Language Models, this to give more background to my next, next article related to land selection for DCs, because obviously there is a huge difference in base requirements between selecting a site for the first or the latter. My mental process was something like: I’m not sure who will really read what I write... hence I would like to start from the basis... hence I need to explain from where and how our modern IT infrastructure came to light. So, here we go!

The Internet

The Internet is often perceived as an abstract, intangible system, akin to a virtual network of ideas connecting billions of people worldwide. In reality, the Internet is a vast and complex physical and logical infrastructure made of giant cables, nodes, routers, and (of course) data centers that together form the titanic backbone that enables seamless global communication and underpins our digital economy. Importantly, while nowadays inseparably interconnected, the Internet is distinct from the World Wide Web: while the first is the material network enabling global connectivity, the Web is an information-sharing system that operates on top of this infrastructure, utilizing various protocols to deliver content.

This network has evolved over decades, growing from an experimental concept into a system that processes vast amounts of data at incredible speeds, supporting applications from streaming media to advanced cloud computing. At its core, the Internet’s development reflects a profound intersection of visionary ideas and technological breakthroughs. What began as theoretical discussions in the 1960s evolved into a global digital infrastructure that defines our modern life. Tracing its history reveals not only the milestones that shaped it but also the physical systems that make it all possible. Understanding this evolution offers valuable insight into the interplay between technology, innovation, and infrastructure.

Conceptual Foundations (1960s): The Birth of Network Ideas

The seeds of the Internet were planted during the 1960s, a time of rapid technological exploration. One of the pivotal figures of this era was J.C.R. Licklider, a computer scientist at the MIT, who proposed the idea of an “Intergalactic Computer Network.” This visionary concept envisioned a world where computers could share resources, exchange data, and communicate seamlessly across geographic boundaries. At a time when most computers were isolated and operated by a single user, this idea was revolutionary.

Licklider’s work set the stage for significant advancements in networking. The introduction of time-sharing systems, which allowed multiple users to access computing resources simultaneously, began to hint at the potential for interconnected systems. Early computers, like the IBM 7090 (IEEE Spectrum), showcased the need for better collaboration between machines, but their limited networking capabilities presented challenges. The development of modems further advanced these ideas by enabling data transmission over telephone lines, creating the first physical pathways for inter-computer communication. These innovations were the foundation of what would later become the Internet.

The ARPANET Era (1969–1980s): The First Physical Networks

The transition from concept to implementation occurred with the creation of ARPANET in 1969. Funded by the U.S. Department of Defense’s Advanced Research Projects Agency (ARPA), ARPANET became the first operational packet-switching network. It connected institutions like UCLA and Stanford Research Institute, proving that distant computers could communicate effectively over long distances.

The first message sent on ARPANET was an attempt to transmit the word “LOGIN”, but the system crashed after sending only “LO” (UCLA). Despite this modest beginning, ARPANET introduced ground-breaking technologies like packet switching. Unlike circuit-switching, which required a dedicated communication line, packet switching broke data into small packets for more efficient and resilient transmission this was made possible by Interface Message Processors (IMPs), the forerunners of modern routers, that were deployed to connect host computers to ARPANET using them as a buffer interface between computers with different kernels.

The idea for the Interface Message Processor (IMP) was suggested by Wesley Clark at the “ARPANET Design Session” held by Lawrence Roberts at the IPTO Principal Investigator meeting in Ann Arbor, Michigan in April, 1967. Roberts’ plan called for each site to write the software to connect their computer to the network, which looked like a lot of work to the attendees since there were so many different kinds of computers and operating systems in use throughout the DARPA community. Clark told Roberts that he thought the design was inside out. After the meeting Roberts stayed behind and Clark elaborated on his concept — deploy a minicomputer called an “interface message processor” at each site to handle the interface to the ARPANET network, so each site would only have to write one interface to the one standard IMP (ARPANET IMP, Interface Message Processor | LivingInternet).

Building ARPANET required a physical backbone, which relied on leased telephone lines. This network expanded over time, creating a system of physical nodes and connections that linked research institutions across the United States. These efforts laid the groundwork for today’s interconnected world, proving that large-scale computer networks were not only feasible but also transformative.

The Standardization Era (1983): Interoperability with TCP/IP

By the early 1980s, ARPANET’s limitations became apparent, particularly as more institutions sought to connect their systems. The solution came in 1983 with the adoption of TCP/IP, a protocol suite developed by Vinton Cerf and Robert Kahn. This marked a pivotal moment in networking history. TCP/IP introduced a dual protocol system: TCP (Transmission Control Protocol), which ensured reliable, ordered, and error-free data transmission, and UDP (User Datagram Protocol), a lightweight, connectionless alternative prioritizing speed over reliability. While TCP was essential for applications like file transfers and email, UDP became the preferred choice for latency-sensitive applications such as video streaming and voice communications. Together, TCP and UDP provided the flexibility to address the growing diversity of networked applications.

The shift to TCP/IP also drove significant advancements in local networking. Ethernet technology, pioneered by Bob Metcalfe, revolutionized communication within organizations by enabling faster and more reliable data transfer. At the same time, routers replaced the earlier Interface Message Processors (IMPs), providing more sophisticated traffic management across interconnected networks. As the physical infrastructure evolved, copper cabling began to give way to early fiber optics, which offered significantly higher bandwidth and improved reliability for long-distance communication. These fiber optic networks not only supported the growing demands of the Internet but also laid the groundwork for modern telecommunications.

The adoption of TCP/IP and these accompanying innovations effectively transformed ARPANET into the modern Internet. By enabling seamless communication between networks with different architectures, this combination of protocol standardization and technological advancements made it possible to scale the Internet’s infrastructure to meet the demands of an increasingly connected world.

The Internet Goes Global (1980s–1990s): Scaling the Backbone

The late 1980s and early 1990s marked the Internet’s transition from a government and academic tool to a public utility. The NSFNET, established by the National Science Foundation, replaced ARPANET as the Internet’s backbone, connecting universities and research institutions with “high-speed” links. This expansion paved the way for broader public access and commercialization.

If you are curious, a T1 line (mentioned in the NSFNET picture above) can transmit data at a speed of 1544 kbps. Compared to standard telephone lines that used a modem to transfer voice and data at a mere 56 kbps. The first version, the Transmission System 1 (T1), was introduced in 1962 in the Bell System, and could transmit up to 24 telephone calls simultaneously over a single transmission line of copper wire. Subsequent specifications carried multiples of the basic T1 (1.544 Mbit/s) data rates, such as T2 (6.312 Mbit/s) with 96 channels, T3 (44.736 Mbit/s) with 672 channels, and others. “Fun” Fact, the first actual fiber optic cable was invented in 1952 by UK based physicist Narinder Singh Kapany, sadly the discovery was not commercialized due to transmission losses… in fact only thirteen years later two British research scientists, Charles Kao and George Hockman discovered that attenuation of fiber optics was caused by impurities in manufacturing. (opticalfibrehistory.co.uk)

Fiber optic cables became the backbone of this growing network, offering unparalleled capacity for data transmission. Regional networks emerged, allowing homes and businesses to connect to the Internet. The introduction of the Domain Name System (DNS) in 1984 made navigation easier by replacing numerical IP addresses with user-friendly domain names. Internet Service Providers (ISPs) began offering access to the network, making the Internet accessible to a wider audience. These developments transformed the Internet into a scalable, user-centric system capable of supporting an ever-expanding range of applications.

In the meantime, on the other side of the pond, in Europe, a significant milestone in the Internet's evolution was taking shape at CERN (the European Organization for Nuclear Research). While the United States was building the infrastructure to connect its networks, CERN focused on creating a system to make information sharing more efficient for its global network of researchers. In 1989, Tim Berners-Lee, a British scientist at CERN, proposed the concept of the World Wide Web. His idea was to develop a system using hypertext to enable researchers to access and share documents easily across the Internet.

Berners-Lee developed the foundational technologies of the Web: Hypertext Markup Language (HTML) for structuring content, the Hypertext Transfer Protocol (HTTP) for communication, and Uniform Resource Locators (URLs) to identify resources. By 1990, the first web browser, WorldWideWeb, and the first website, hosted at CERN, were operational. This innovation complemented the physical Internet infrastructure by creating a user-friendly layer that revolutionized how people accessed information.

CERN’s internal networks, combined with its collaborative approach, became an early example of how Europe leveraged the Internet to enhance scientific research and knowledge exchange. The World Wide Web’s public release in 1993 marked a pivotal moment, accelerating the commercialization and widespread adoption of the Internet globally (The birth of the Web | CERN).

Undersea Cables and the Modern Internet (1990s–2000s): Global Connectivity

The 1990s and 2000s saw the Internet become a truly global system, thanks to the deployment of transoceanic fiber optic cables. These undersea cables connected continents, enabling real-time communication on a global scale. Innovations in submarine cable technology, such as optical amplification and dense wavelength division multiplexing (DWDM), exponentially increased data capacity, supporting the rise of international commerce, media, and collaboration.

If you are curious, the role of optical fibers in modern telecommunications cannot be overstated. Optical fiber communications operate in specific wavelength regions, the so-called “telecom windows": the C-band, operating around 1.5 to 1.6 μm, is particularly significant due to its low propagation loss and the availability of high-performance amplifiers. Recent advancements, such as those achieved by researchers at Aston University, have demonstrated the potential to expand the usable spectrum within optical fibers. By accessing previously unused E and S bands alongside the standard C and L bands, they achieved a record-breaking transmission rate of 301 terabits per second!!! This innovation not only addresses the growing demand for data but also offers a sustainable approach to increasing network capacity without requiring new infrastructure. (Aston University researchers send data 4.5 million times faster than average broadband | Aston University)

Simultaneously, Internet Exchange Points (IXPs) emerged as critical hubs for managing inter-network traffic, optimizing data flow, and reducing latency. Data centers, which initially served as simple server rooms, evolved into critical nodes in the Internet’s physical architecture. These facilities host vast amounts of data and applications, forming the backbone of the modern digital economy.

The Evolution Continues

The Internet’s journey from isolated networks to a globally connected infrastructure is a story of relentless innovation. Its physical backbone, from early modems and telephone lines to fiber optics and undersea cables, has grown to support an interconnected world. Today, data centers, satellite networks, and edge computing are expanding the Internet’s capabilities, pushing the boundaries of what is possible.

As we look to the future, advancements in quantum networking and decentralized systems promise to redefine the Internet’s infrastructure. Behind every digital connection lies a physical network built on decades of technological progress and visionary thinking. The Internet’s evolution is far from over, and its next chapter is already being written.