what is a cdn

The Internet has evolved. These days everyone expect more from websites. The overall website performance became a major task for modern web developers since loading speed became critically important for overall user experience. With so many individuals accessing content online, an advanced method of transfer, organization and management had to be implemented.

Let’s say you have a server that hosts your whole website located in San Antonio, Texas. Should one of your end-users in Dubai request your content, it will take a bloody long time for what’s stored in the Southern US to arrive halfway around the world. A content delivery network provides a solution for this latency by placing your files at a point of presence connection near the final user, allowing the data to flow across a shorter distance. This technology is the perfect solution for resource-consuming content.

cdn content replication
This practice is known as content replication. Instead of serving video, audio, JavaScripts, CSS and images from a single shared hosting account, most CDNs have dozens of edge servers around the world that replicate your content. In other words, CDNs serve identical content depending on where the end-user is located.

CDNs were designed to be effective even during the busiest peak times or during sudden demand spikes. Most large delivery networks consist of thousands of servers so hundreds of thousands end-users can access identical content simultaneously.

cdn example

Selection is measured by choosing locations that have the fewest hops, number of seconds from the client or the highest availability of well-performing servers. As a result, the content is delivered way faster. This significantly improves user experience and satisfaction as well as maximizes the overall performance across the network.

Requests for content are directed through series of algorithms to the nodes. The number of nodes in a CDN varies depending on the architecture of the system. Many CDNs reach thousands of nodes with tens of thousands of servers located at remote points of presence (PoPs). The sets of PoPs, defined by the geographic coverage, are called “edges” or “edge networks” as they would be the closest edge of a CDN to the end-user.

The specific nodes are available from across many locations and backbones. Since they are linked, the nodes communicate with one another to fulfill requests for content which is transparently distributed to improve the delivery procedure. Optimizing the process typically includes reducing bandwidth costs, increasing the global availability of content and improving user performance by reducing page loading times.

CDN

As it was previously mentioned, CDNs send content to the end-users from a server closest to them with minimal delay. Therefore, the issues of variations in latency with each passing moment (causes jittering in audio and video) are minimized. Also, CDNs provide a fail-safe environment. During widespread attacks the content will continue to be available. Hence, the system provides efficient backup, storage and data capacity which can benefit individual and business users who currently rely on online backup services.

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CDN77

CDN77

45 votes, average: 4.24 out of 545 votes, average: 4.24 out of 545 votes, average: 4.24 out of 545 votes, average: 4.24 out of 545 votes, average: 4.24 out of 5 (84.89%, 45 votes)

27 POPs (7 in North America)
$0.049/GB (USA & EU traffic)

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Amazon CloudFront

Amazon CloudFront

34 votes, average: 4.53 out of 534 votes, average: 4.53 out of 534 votes, average: 4.53 out of 534 votes, average: 4.53 out of 534 votes, average: 4.53 out of 5 (90.59%, 34 votes)

52 POPs (20 in North America)
$0.085/GB (USA & EU traffic)

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MaxCDN

MAXCDN

51 votes, average: 4.08 out of 551 votes, average: 4.08 out of 551 votes, average: 4.08 out of 551 votes, average: 4.08 out of 551 votes, average: 4.08 out of 5 (81.57%, 51 votes)

16 POPs (9 in North America)
$0.079/GB (USA & EU traffic)

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