Introduction to Cloud DCNs
A cloud data center (DC) is a new type of DC based on cloud computing architecture, where the computing, storage, and network resources are loosely coupled. Within a cloud DC, various IT devices are fully virtualized, while also being highly modularized, automated, and energy efficient. In addition, a cloud DC features virtualized servers, storage devices, and applications, enabling users to leverage various resources on demand. Automatic management of physical and virtual servers, service processes, and customer service charging is also provided. Starting with cloud computing and virtualization, this chapter describes the software-defined networking (SDN) technology used by cloud data center networks (DCNs) to tackle the challenges introduced by this new architecture.
Before examining cloud DCNs in more detail, we should first take a closer look at cloud computing. The pursuit of advanced productivity is never ending. Each industrial revolution has represented a leap in human productivity, as our society evolved from the mechanical and electric eras through to the current automatic and intelligent era.
Since the 1980s, and owing to the advances of global science and technology, culture, and the economy, we have gradually transitioned from an l
industrial society to an information society. By the mid-1990s, economic globalization had driven the rapid development of information technologies, with the Internet becoming widely applied by all kinds of businesses. As the global economy continues to grow, cracks have begun to appear in the current processes of enterprise informatization. Constrained by complex management modes, spiraling operational expenses, and weak scale-out support, enterprises require effective new information technology solutions. Such requirements have driven the emergence of cloud computing.
The US-based National Institute of Standards and Technology (NIST) defines the following five characteristics of cloud computing:
- • On-demand self-service: Users can leverage self-services without any intervention from service providers.
- • Broad network access: Users can access a network through various terminals.
- • Resource pooling: Physical resources are shared by users, and resources in a pool are region-independent.
- • Rapid elasticity: Resources can be quickly claimed or released.
- • Measured service: Resource measurement, monitoring, and optimization are automatic.
“On-demand self-service” and “broad network access” express enterprises’ desire for higher productivity and particularly the need for service automation. “Resource pooling” and “rapid elasticity” can be summarized as flexible resource pools, while “measured services” emphasize that operational support tools are required to tackle the considerable challenges of automation and virtualization. More intelligent and refined tools are also required to reduce the operating expense (ОРЕХ) of enterprises.
Cloud computing is no longer just a term specific to the IT field. Instead, it now represents an entirely new form of productivity, as it creates a business model for various industries, drives industry transformation, and reshapes the industry chain. Cloud computing introduces revolutionary changes to traditional operations and customer experience, and seizing the opportunities of cloud computing will boost growth throughout the industry.
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