Content Overview Initially, TCP/IP networks relied on simple distance vector routing protocols and classful 32-bit IP addressing. These technologies offered a limited capacity for growth. Network designers must now modify, redesign, or abandon these early technologies to build modern networks that can scale to handle fast growth and constant change. This module explores networking technologies that have evolved to meet this demand for scalability. Scalability is the capability of a network to grow and adapt without major redesign or reinstallation. It seems obvious to allow for growth in a network, but growth can be difficult to achieve without redesign. This redesign may be significant and costly. For example, a network may provide a small company with access to e-mail, the Internet, and shared files. If the company tripled in size and demanded streaming video or e-commerce services, could the original networking media and devices adequately serve these new applications? Most organizations cannot afford to re-cable or redesign their networks when users are relocated, new nodes are added, or new applications are introduced. Good design is the key to the capability of a network to scale. Poor design, not an outdated protocol or router, will prevent a network from scaling properly. A network design should follow a hierarchical model to be scalable. This lesson starts by introducing the network as the platform for the Information age. The Cisco vision of the future Intelligent Information Network (IIN) and the Service-Oriented Network Architecture (SONA) are then introduced, followed by the Cisco Enterprise Architectures and how they align with the Cisco Enterprise Composite Network Model (ECNM). Next, the key characteristics of scalable internetworks, traffic patterns in converged networks, and how routing protocols fit into these models are discussed. This module also introduces the topology of the International Travel Agency (ITA), on which the labs exercises are based.
Content 1.1 IIN, SONA, and the ECNM 1.1.1 Technological Revolution Cycles Since the late 1700s, there have been five technology revolutions. Each of these technology revolutions lasted about half a century. The five technological revolutions are: Each cycle has followed the same general pattern of development and adoption. They begin with a low degree of technological maturity and market saturation, quickly followed by rapid innovation and growth. In time, expectation is countered by reality, resulting in a cataclysmic revaluation of perceived value. A turning point is reached when the value of the original innovation is realized, and the need for standards and regulations to manage its adoption are recognized.
Content 1.1 IIN, SONA, and the ECNM 1.1.2 The Network as the Platform After reaching the turning point, each successive age of innovation has given rise to a new “platform,” with new surrounding ecosystems that maximize the value of the platform to both the supplier and the user. Figure highlights the various technology revolutions and their associate platform. The age of information is now at a critical turning point where the promise of Internet technology still exists, and innovators are rethinking how to harness and deliver it to businesses and consumers alike. Rather than taking existing business models and simply automating them onto a network, innovators are starting with the network and re-architecting the business models and processes around this new platform. The network as a platform is about much more then IT innovation, it is about the way the world performs business. It is as expansive as what the railway system did when it was fully adopted, when today's distribution systems of plane, trains, and automobiles were fully realized. It changes business models, it changes the way people interact, and it changes the world.
Content 1.1 IIN, SONA, and the ECNM 1.1.3 The Intelligent Information Network (IIN) For competitive reasons, many enterprises quickly deploy new technologies and applications, which often lead to the deployment of disparate systems. Vital networked resources, applications, and information assets remain largely unlinked, despite a large investment in IT resources. In fact, it is not uncommon for organizations to have hundreds of “siloed” applications and databases that cannot communicate with each other. For example, sales applications and databases cannot be accessed easily by customer service or purchasing departments without creating different overlay networks that join applications and information. These disparate systems are also difficult and costly to manage because they result in distributed resources that are uncoordinated and underused. The Intelligent Information Network (IIN) is a strategy that addresses the evolving role of the network as the platform within business. It directly addresses the desire to align IT resources with business priorities. The resulting network delivers active participation, process optimization, service delivery, and application responsiveness, which results in better IT awareness. The nature of the enterprise network is evolving from a low-function communication service to a high-function enterprise nervous system. An intelligent network builds on an existing infrastructure foundation and turns the traditional IT “cost center” into a strategic tool that helps enable sophisticated IT functionality, such as virtualization, telepresence, application integration, and optimization of IT processes. IIN encompasses these features: The IIN offers much more than basic connectivity, bandwidth for users, and access to applications. It offers end-to-end functionality and centralized, unified control that promotes true business transparency and agility. The IIN technology vision offers an evolutionary approach that consists of three phases in which functionality can be added to the infrastructure as required: