What is a CDN and how does it speed up your website?

A CDN is a way to improve website load times and meet users' speed expectations. It is also a way to store images, video and other content so international visitors can reach it without delay. What is a CDN? How does a CDN speed up access from abroad? If that is what you need, read on and we will go through it together.

1. What is a CDN?

CDN stands for Content Delivery Network. A CDN is a system of many edge server clusters that copy content from the origin server and handle user requests. So that people around the world can reach a website easily, CDN server clusters are placed all over the globe.

How a CDN is structured and how it works

A CDN can be divided into points of presence (PoPs) and edge servers. The two are not separate: a PoP is in fact a group of edge servers. Edge servers combine into PoPs of different sizes, and dozens of PoPs around the world make up a complete CDN. Edge servers work in a simple way: they hold copies of content identical to the website on the origin server. Users who connect to an edge server get the same look and the same functions as on the origin server. Access is much faster, though, because the CDN automatically routes each user's connection to the nearest edge server. That is how a CDN lets users anywhere in the world reach your website easily and quickly. The location of PoPs has a big effect on how well a CDN performs, although the configuration and number of edge servers matter too. The closer a CDN's PoPs sit to the backbones of the internet, to routes maintained by many companies and to large network hubs, the better its performance and speed.

2. What are the benefits of using a CDN?

According to statistics, more than 19 million websites worldwide use CDN services. So what are the benefits of a CDN?

Lower network latency, much faster access

• As noted above, a CDN routes each user's request to the edge server closest to them. The shorter the distance to the server, the faster the connection. You notice this when playing international online games: games with servers in Vietnam or nearby, such as Thailand or Singapore, lag far less.
• Another good example is Google. Google Search loads fast wherever you are, because Google runs a huge CDN with PoPs at key internet exchange points around the world. There is always an edge server holding a perfect copy of Google Search near you. Even when a cable is cut, access to Google Search is affected less than access to other websites.
• Facebook, YouTube, Wikipedia and the other most popular international sites load just as fast, thanks to widely distributed CDN systems.
• A CDN helps raise your conversion rate and lower your bounce rate. Today's users have little patience for slow websites and will leave if pages load too slowly. Keeping them on the page, with features that run smoothly, encourages them to take action and lifts your conversion rate.

Better server performance

• A CDN improves not only speed but also the performance of your origin server. Without a CDN, every user request has to be handled by the origin server. The more visitors, the harder the server works, which uses more bandwidth and over time hurts the server's performance.
• To keep the server and website from overloading and suddenly going down, you have to spend more on a stronger server and more bandwidth. But upgrading a server is a hard problem and costs a lot.
• A CDN takes a lot of that load off your origin server, because edge servers handle visitor requests on its behalf. Edge servers usually hold only static content, but luckily most web content is static. Advanced CDNs can even handle dynamic content, improving origin server performance further.

Higher reliability and availability

• Keeping a website available is critical. A website with low reliability that goes down easily causes serious problems.
• Using a CDN to minimize the chance of your site being unreachable is essential, especially if you plan to grow. With a CDN you have dozens of copies of your original content on edge servers. If something goes wrong with the origin server or some of the edge servers, others remain safe. You can keep serving visitors until the problem is fixed.

Reach more customers and improve the user experience

A CDN is a large, global network of PoPs and edge servers. Using a CDN lets you widen your audience by geography through your website, which extends the market you already have to countries across the region.

If you want to serve customers in the US, Japan, China or Australia, you don't have to go anywhere: you can buy and use a server in Vietnam at a price that fits your budget. The only thing you need is a CDN service with PoPs near the regions where you want to do business.

This way you can easily reach your target customers abroad, remove the barrier of distance, and bring in more revenue by finding international customers more easily.

Stronger security

• Like performance, the way a CDN works, handling less on the origin server, also adds to the system's security.
• Edge servers handle user problems and requests, but they are only simple caches holding copies. If one is attacked, the content and operation of the origin server are not affected.
• In that case, the CDN simply shuts down that edge server and redirects user requests to another one that is still available. CDN services also come with solid security for their whole system, so it is not easy for an edge server to be hacked. Most edge servers today have SSL certificates, along with other important security features such as hotlink protection and token security.

Lower costs and less effort

• You will pay to rent a CDN service. But compared with what you would spend upgrading servers and fixing problems, it is a worthwhile investment.
• You can put off upgrading your server thanks to the scale and power of CDN systems and still serve visitors well. You only need a server strong enough to hold your content and handle a few other requests. You also avoid the cost of maintaining the server and upgrading security and protection against cyberattacks.

Downsides of a CDN:

However, not every customer or website owner should use a CDN service. A CDN is not a double-edged sword; it simply doesn't suit every situation. Most CDNs are built to serve international traffic, with PoPs around the globe. If your website is small or medium and most of your audience is near the origin server, a CDN is unnecessary. You won't use any edge servers and will still pay a monthly fee. Also, as we said, a CDN only saves money as a long-term investment. Upfront, you pay to sign up. Many CDN services are advertised as free, but in practice they are only partly free or free for a limited time, which is a trial period. After it ends you must pay to keep using the CDN. In short, if you want a good CDN service to improve your website, you have to pay for it. The amount is fairly large at first, but it proves its value as time goes by. Another downside of a CDN is that it takes technical skill to run and maintain. Knowledge is not enough; you also need experience to deploy the system well, even though providers try to simplify setup. Updating content on edge servers or handling difficult situations is not easy either.

When should you use a CDN for your website?

When should you use a CDN for your website? After weighing everything, the best answer depends on your scale and your target audience. If your website targets the domestic market, or a single city such as Ho Chi Minh City or Hanoi, you should not use a CDN. It would be unnecessary and costly, since no edge server would be closer to your customers than the origin server. If your business covers the whole country, you can use a large domestic CDN provider. These CDNs have PoPs in major cities with dense populations and network connections. A CDN speeds up access for users in those places even further, improving their experience and bringing your website many benefits. If your website targets overseas markets, a CDN is definitely a worthwhile, recommended way to optimize content, speed up international access, improve server performance and gain many other benefits. You know what your website is missing, but … you is never are not a website management expert and lack the skills for:

• Build a pixel-perfect design that looks exactly the way you want
• Build the features you need to attract users
• Speed and security optimization
• Meet every SEO requirement
• …

MONA Media offers website optimization and upgrade plans tailored to your needs so your website turns out exactly the way you want. That covers what a CDN (content delivery network) is and its pros and cons. A CDN speeds up access to your website, but whether to use one depends on the geographic distance between your origin server and your target audience. We hope this article from Mona Media helps you make the right call on investing in a CDN and get strong results from it.