CHAPTER 1
Introduction

If the seventeenth and early eighteenth centuries are the age of clocks, and the later eighteenth and the nineteenth centuries constitute the age of steam engines, the present time is the age of communication and control.

Norbert Wiener (from the 1948 edition of Cybernetics: or Control and Communication in the Animal and the Machine).

It is unfortunate that we don't remember the exact date of the extraordinary event that we are about to describe, except that it took place sometime in the Fall of 1994. Then Professor Noah Prywes of the University of Pennsylvania gave a memorable invited talk at Bell Labs, at which two authors1 of this book were present. The main point of the talk was a proposal that AT&T (of which Bell Labs was a part at the time) should go into the business of providing computing services-in addition to telecommunications services-to other companies by actually running these companies' data centers. "All they need is just to plug in their terminals so that they receive IT services as a utility. They would pay anything to get rid of the headaches and costs of operating their own machines, upgrading software, and what not."

Professor Prywes, whom we will meet more than once in this book, well known in Bell Labs as a software visionary and more than that-the founder and CEO of a successful software company, Computer Command and Control-was suggesting something that appeared too extravagant even to the researchers. The core business of AT&T at that time was telecommunications services. The major enterprise customers of AT&T were buying the customer premises equipment (such as private branch exchange switches and machines that ran software in support of call centers). In other words, the enterprise was buying things to run on premises rather than outsourcing things to the network provider!

Most attendees saw the merit of the idea, but could not immediately relate it to their day-to-day work, or-more importantly-to the company's stated business plan. Furthermore, at that very moment the Bell Labs computing environment was migrating from the Unix programming environment hosted on mainframes and Sun workstations to Microsoft Office-powered personal computers. It is not that we, who "grew up" with the Unix operating system, liked the change, but we were told that this was the way the industry was going (and it was!) as far as office information technology was concerned. But if so, then the enterprise would be going in exactly the opposite way-by placing computing in the hands of each employee. Professor Prywes did not deny the pace of acceptance of personal computing; his argument was that there was much more to enterprises than what was occurring inside their individual workstations-payroll databases, for example.

There was a lively discussion, which quickly turned to the detail. Professor Prywes cited the achievements in virtualization and massive parallel-processing technologies, which were sufficient to enable his vision. These arguments were compelling, but ultimately the core business of AT&T was networking, and networking was centered on telecommunications services.

Still, telecommunications services were provided by software, and even the telephone switches were but peripheral devices controlled by computers. It was in the 1990s that virtual telecommunications networking services such as Software Defined Networks-not to be confused with the namesake development in data networking, which we will cover in Chapter 4-were emerging on the purely software and data communications platform called Intelligent Network. It is on the basis of the latter that Professor Prywes thought the computing services could be offered. In summary, the idea was to combine data communications with centralized powerful computing centers, all under the central command and control of a major telecommunications company. All of us in the audience were intrigued.

The idea of computing as a public utility was not new. It had been outlined by Douglas F. Parkhill in his 1966 book [1].

In the end, however, none of us could sell the idea to senior management. The times the telecommunications industry was going through in 1994 could best be characterized as "interesting," and AT&T did not fare particularly well for a number of reasons.2 Even though Bell Labs was at the forefront of the development of all relevant technologies, recommending those to businesses was a different matter-especially where a proposal for a radical change of business model was made, and especially in turbulent times.

In about a year, AT&T announced its trivestiture. The two authors had moved, along with a large part of Bell Labs, into the equipment manufacturing company which became Lucent Technologies and, 10 years later, merged with Alcatel to form Alcatel-Lucent.

At about the same time, Amazon launched a service called Elastic Compute Cloud (EC2), which delivered pretty much what Professor Prywes had described to us. Here an enterprise user-located anywhere in the world-could create, for a charge, virtual machines in the "Cloud" (or, to be more precise, in one of the Amazon data centers) and deploy any software on these machines. But not only that, the machines were elastic: as the user's demand for computing power grew, so did the machine power-magically increasing to meet the demand-along with the appropriate cost; when the demand dropped so did the computing power delivered, and also the cost. Hence, the enterprise did not need to invest in purchasing and maintaining computers, it paid only for the computing power it received and could get as much of it as necessary!

As a philosophical aside: one way to look at the computing development is through the prism of dialectics. As depicted in Figure 1.1(a), with mainframe-based computing as the thesis, the industry had moved to personal-workstation-based computing-the antithesis. But the spiral development-fostered by advances in data networking, distributed processing, and software automation-brought forth the Cloud as the synthesis, where the convenience of seemingly central on-demand computing is combined with the autonomy of a user's computing environment. Another spiral (described in detail in Chapter 2) is depicted in Figure 1.1(b), which demonstrates how the Public Cloud has become the antithesis to the thesis of traditional IT data centers, inviting the outsourcing of the development (via "Shadow IT " and Virtual Private Cloud). The synthesis is Private Cloud, in which the Cloud has moved computing back to the enterprise but in a very novel form.

Figure 1.1 Dialectics in the development of Cloud Computing: (a) from mainframe to Cloud; (b) from IT data center to Private Cloud.

At this point we are ready to introduce formal definitions, which have been agreed on universally and thus form a standard in themselves. The definitions have been developed at the National Institute of Standards and Technology (NIST) and published in [2]. To begin with, Cloud Computing is defined as a model "for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources (e.g., networks, servers, storage, applications, and services) that can be rapidly provisioned and released with minimal management effort or service provider interaction." This Cloud model is composed of five essential characteristics, three service models, and four deployment models.

The five essential characteristics are presented in Figure 1.2.

Figure 1.2 Essential characteristics of Cloud Computing. Source: NIST SP 800-145, p. 2.

The three service models, now well known, are Software-as-a-Service (SaaS), Platform-as-a-Service (PaaS), and Infrastructure-as-a-Service (IaaS). NIST defines them thus:

1. Software-as-a-Service (SaaS). The capability provided to the consumer is to use the provider's applications running on a Cloud infrastructure. The applications are accessible from various client devices through either a thin client interface, such as a web browser (e.g., web-based e-mail), or a program interface. The consumer does not manage or control the underlying Cloud infrastructure including network, servers, operating systems, storage, or even individual application capabilities, with the possible exception of limited user-specific application configuration settings.
2. Platform-as-a-Service (PaaS). The capability provided to the consumer is to deploy onto the Cloud infrastructure consumer-created or acquired applications created using programming languages, libraries, services, and tools supported by the provider. The consumer does not manage or control the underlying Cloud infrastructure including network, servers, operating systems, or storage, but has control over the deployed applications and possibly configuration settings for the application-hosting environment.
3. Infrastructure-as-a-Service (IaaS). The capability provided to the consumer is to provision processing, storage, networks,...