What is a CDN?

Definition of CDN

CDN (Content Delivery Network) meaning a network composed of geographically distributed proxy servers and data centers. The goal is to provide high availability and performance by spatially distributing the service near end-users. CDNs emerged in the late 1990s to address the performance bottlenecks of the Internet as it was becoming a mission-critical medium for individuals and businesses. Since then, CDNs have evolved to serve a large portion of today's Internet content, including web objects (text, graphics, and scripts), downloadable objects (media files, software, documents), applications (e-commerce, portals), live streaming media, on-demand streaming media, and social media websites.

The Access Process/Acceleration Principle of CDN

CDN acceleration technology generates multiple mirror images of the original website during the traditional website access process, and stores them on cache servers in different regions and on different lines. When a user accesses a website, the scheduling system routes or guides the user's request to the cache server that is closest to the user's access network or has the best access effect, and this cache server provides the content service for the user. Compared to direct access to the source station, this method shortens the network distance between users and content, thereby achieving an acceleration effect. CDN is a composite technology comprising several key components: origin server, cache servers, and intelligent DNS.

1. Origin servers: The origin server refers to the original site where content is published. All file additions, deletions, and modifications to the website occur on the origin server. Additionally, the objects fetched by the cache servers all come from the origin server.
2. Cache Servers: Cache servers directly provide resources to user access and consist of one or several servers. When a user initiates a request, their access request is directed by intelligent DNS to the nearest cache server. If the requested content is already in the cache, it is directly returned to the user. If the required content is not cached, the cache server fetches the content from nearby cache servers or directly from the origin server before returning it to the user.
3. Intelligent DNS: Intelligent DNS is the core of the entire CDN technology. It primarily directs user access requests to the nearest cache server based on the user's location. Through intelligent DNS resolution, users access servers within the same service provider, mitigating the issue of slow interconnection between networks in different regions, thereby achieving acceleration. The emergence of intelligent DNS has overturned the traditional approach of one domain corresponding to one mirror, making it more convenient for users to access websites.

Benefits of CDN

CDNs carry a large portion of the world's internet traffic. They help solve the toughest challenges of delivering content over the internet. From small and medium content providers to the world's large corporations, businesses everywhere take advantage of key CDN benefits to provide a seamless web experience to their customers. Some of its major advantages include:

1. Improving website load times: By distributing content to CDN servers near visitors (and other optimization measures), visitors experience faster page loading times. Since visitors are more likely to leave slow-loading websites, CDNs can reduce bounce rates and increase the time people spend on the site. In other words, the faster the website speed, the longer users stay.
2. Improve origin server load: By distributing traffic across multiple server nodes, CDN can reduce the load on the origin server and avoid single points of failure.
3. Always get the latest version: For example, by using Font Awesome CDN, you will always have access to the latest version of Font Awesome without the need for manual updates.
4. Increased availability and reliability: The distributed architecture of CDN can automatically switch traffic to other available nodes when a node fails, ensuring continuous content availability.
5. Enhanced security: CDN offers various security features, such as DDoS attack protection, SSL encryption, and Web Application Firewall, to improve the security of websites or applications.
6. Reduced bandwidth costs: The bandwidth consumption cost of website hosting is a major expense for websites. Through caching and other optimizations, CDNs can reduce the amount of data that the origin server must provide, thereby lowering the hosting costs for website owners.
7. Offload traffic: With the explosive growth of online streaming and other rich media services, and higher user expectations about web performance across multiple device types, many of today's network service providers are finding their content distribution networks to be highly stressed. By responding to a request for web content with a cached version from servers closer to the end user, a CDN can offload traffic from content servers and improve the web experience.

EdgeOne CDN Service: Not just Acceleration

Compared to CDN, Tencent EdgeOne not only offers a broader range of features but also serves as a comprehensive one-stop platform that addresses both acceleration and security requirements. Its risk-avoidance capabilities allow billing based on clean traffic after cleansing, eliminating concerns about unexpected high bills. At the same time, operational efficiency is further improved, such as free certificate automatic updates, site-level batch management, and saving a lot of tedious steps. It also supports personalized capability customization: Rule Engines and Edge Functions can flexibly adapt to different business scenarios. The billing model is more reasonable, offering subscription packages and excess pay-as-you-go.

1. Cost savings: A one-stop solution is more cost-effective than purchasing individual products separately. Billing based on clean traffic after protection avoids unexpected high bills, making budget management easier.
2. Increased efficiency and speed: The integration of acceleration and security analysis helps users quickly locate problems; configuration and operation management are more efficient within a single console.
3. Inclusive security: Enjoy advanced Web protection and platform-level DDoS protection at a low cost, combined with advanced semantic analysis engines and intelligent BOT analysis, accurately identifying malicious requests and reducing false positives.
4. Flexible configuration: Edge functions, rule engines, and other product capabilities enable more personalized and customized business solutions, allowing flexible adaptation to different business scenarios.
5. Audio/Video Acceleration: Based on Tencent's many years of online video operations experience and optimized for online audio/video playback business scenarios. EdgeOne can support a high number of concurrent requests during peak hours while effectively ensuring high availability of the service and satisfactory media transfer speed, helping you deliver a stable, smooth, and rich-featured watch experience.