The internet is a collection of numerous networks or datacenters. The growth of the world-wide-web and related technologies along with proliferation of wireless technologies, cloud computing, etc. is leveraging users to access the internet with multiple devices in addition to computers. Web servers deployed in networks on the internet cater to most of the user requests on the internet. But, when web servers are located in one single location it becomes increasingly difficult to handle multiple workloads. This has an effect on website performance and efficiency is reduced significantly. Further, users access a variety of applications such as interactive multimedia apps, streaming audio and video along with static and dynamic web pages across millions of websites which require efficient and robust network infrastructures and systems. In order to balance the load on infrastructures and to provide content quickly to end users CDNs are deployed in data centers.
Content Delivery Networks (CDN) is a system of servers deployed in different geographical locations to handle increased traffic loads and reduce the time of content delivery for the user from servers. The main objective of CDN is to deliver content at top speed to users in different geographic locations and this is done by a process of replication. CDNs provide web content services by duplicating content from other servers and directing it to users from the nearest data center. The shortest possible route between a user and the web server is determined by the CDN based on factors such as speed, latency, proximity, availability and so on. CDNs are deployed in data centers to handle challenges with user requests and content routing.
CDNs are used extensively by social networks, media and entertainment websites, e-commerce websites, educational institutions, etc. to serve content quickly to users in different locations. Organizations by implementing CDN solutions stand to gain in many ways that include,
- Faster content load / response time in delivering content to end users.
- Availability and scalability, because CDNs can be integrated with cloud models
- Redundancy in content, thus minimizing errors and there is no need for additional expensive hardware
- Enhanced user experience with CDNs as they can handle peak time loads
- Data integrity and privacy concerns are addressed
The benefits of CDNs are more emphasized by examining its usage in a few real time application areas. Some common application areas include,
- E-Commerce: E-commerce companies make use of CDNs to improve their site performance and making their products available online. According to Computer World, CDN provides 100% uptime of e-commerce sites and this leads to improved global website performance. With continuous uptime companies are able to retain existing customers, leverage new customers with their products and explore new markets, to maximize their business outcomes.
- Media and Advertising: In media, CDNs enhance the performance of streaming content to a large degree by delivering latest content to end users quickly. We can easily see today, there is a growing demand for online video, and real time audio/video and other media streaming applications. This demand is leveraged by media, advertising and digital content service providers by delivering high quality content efficiently for users. CDNs accelerate streaming media content such as breaking news, movies, music, online games and multimedia games in different formats. The content is made available from the datacenter which is nearest to users’ location.
- Business Websites: CDNs accelerate the interaction between users and websites, this acceleration is highly essential for corporate businesses. In websites speed is one important metric and a ranking factor. If a user is far away from a website the web pages will load slowly. Content delivery networks overcome this problem by sending requested content to the user from the nearest server in CDN to give the best possible load times, thus speeding the delivery process.
- Education: In the area of online education CDNs offer many advantages. Many educational institutes offer online courses that require streaming video/audio lectures, presentations, images and distribution systems. In online courses students from around the world can participate in the same course. CDN ensures that when a student logs into a course, the content is served from the nearest datacenter to the student’s location. CDNs support educational institutes by steering content to regions where most of the students reside.
In the internet, closer is always better to overcome problems in latency and performance, CDNs are seen as an ideal solution in such situations. Since CDNs share digital assets between nodes and servers in different geographical locations, this significantly improves client response times for content delivery. CDN nodes or servers deployed at multiple locations in data centers also take care of optimizing the delivery process with users. However, the CDN services and the cost are worked out in SLAs with the data center service provider.