Content Delivery Networks
After reading this chapter, you should be able to perform the following tasks:
Explain the Internet architecture process.
Define a Content Delivery Network (CDN).
Define the components of a CDN.
Explain some of the CDN Architectures that apply CDN components.
As the Internet continues to grow and evolve, more and more data must be delivered from place to place. Many feature-rich applications are also being deployed to enhance productivity and accomplish even more with technology. The Internet Business applications that were discussed earlier, such as e-commerce and e-learning, are some of the applications that companies can now deploy to set new standards for their business operations. The challenge is that as more data (applications and files) is added to the network, the greater the potential for a slower user experience.
Content Delivery Networks (CDNs) enhance the end user's experience by overcoming some inherent flaws in the Internet's anatomy and provide a solution to what was once a major challenge. CDNs are architectures in and of themselves that sit on top of, and complement, a Layer 2/Layer 3 architecture. This chapter covers how CDNs increase overall network performance by solving existing challenges, presents the components of a CDN solution, and provides recipe-based solutions that help in deploying a CDN architecture.
Traditional Web Growth
Internet web sites of the world have evolved over time to meet the needs of the end customer. As traffic grew, web sites also had to grow to serve their customer base. In the beginning, to minimize complexity and cost, most web sites began with a Centralized Architecture with one point of presence. A tremendous growth in Internet traffic followed. As the amount of traffic grew, so did the size of content. To accommodate the growth as the web sites' traffic increased, servers and bandwidth were added. Figure 5-1 reflects the central storage growth of a company's World Wide Web presence.
Figure 5-1 Traditional World Wide Web Growth
The next section addresses the challenges raised by web site growth.