What Is a Video CDN?
A content delivery network (CDN) is a set of servers that cache and deliver content over the Internet. Each server is known as a point of presence (PoP).
Whenever a user requests content from a website, the CDN caches the content in a PoP physically near to the user. When another user from the same location requests the same content, they can access it very quickly. Thus, a globally distributed CDN can improve website performance by delivering content more efficiently than a single origin server.
A video CDN is a CDN optimized to support the delivery of video streams. Streaming video using a CDN ensures that your stream can be viewed by a global audience, minimizes latency and buffering time, and prevents the origin server from being overwhelmed by requests.
Most CDNs can cache and deliver video content, just like they deliver HTML, images, and other web content. However, video CDNs are built specifically for streaming video, and include special technology and caching optimizations that provide higher performance for streaming video content.
This is part of a series of articles about Website performance.
In this article:
- Why Do You Need a Dedicated CDN for Video?
- Benefits of a CDN for Video Streaming
- Video CDN Providers
- How Do Video CDNs Work?
- Cloudinary Multi-CDN Solution Auto-Selects Best CDN for Optimal Per-User Experience
Why Do You Need a Dedicated CDN for Video?
Whether you are starting a live streaming service, a video on demand (VOD) service, or just streaming video to users from your website, you’ll need to find a good video hosting provider and create compelling content. But without a great user experience, you will not be able to retain viewers and achieve your goals—whether they are marketing goals or monetization.
Today’s video users have a wealth of video content to choose from, and cannot tolerate delays and buffering lag. This makes it critical to use a video CDN to ensure that wherever in the world users are, they will access your video streams with high performance and a smooth viewing experience.
Related content: Read our guide to Image CDN (coming soon)
Benefits of a CDN for Video Streaming
Here are key benefits of video CDN:
Scalability
A CDN is a fast and reliable way to deliver content to many viewers worldwide. It can accommodate spikes of viewing and live audiences larger than expected.
Quality
A CDN helps improve the user experience of video streaming. It employs speedy superhighways to send video streams to large audiences worldwide, minimizing delays and buffering. Unlike Internet Service Provider (ISP) and locals network that can slow delivery during the first and last leg, a video CDN can bypass traffic passing in between.
Speed
CDNs can quickly distribute content to edge servers, ensuring content delivered across servers is not bogged down by the geographical distance between end-users and servers or local network conditions.
Reliability and security
CDNs employ redundancy to provide an extra layer of protection. It can help prevent attacks like Distributed Denial of Service (DDoS) that attempt to shut down or breach sites or resources by flooding them with numerous, simultaneous requests. A redundant CDN employs multiple access points to enable failover.
Affordable infrastructure
CDN services enable broadcasters to outsource maintenance and infrastructure costs while benefiting from a global delivery power. It is more affordable for most organizations than building their own global network of servers.
Reduced latency
Videos load and play faster the closer the content is to the viewer. CDNs typically have servers close to many viewers, bringing content closer to viewers even if the stream’s point of origin is more remote. It helps minimize the distance to viewers and reduce latency.
Servers
CDN services offer a network of servers. Broadcasters can use these servers to ensure that the origin server does not become overwhelmed by streaming requests. It enables you to use hundreds of servers, instead of one, to handle streaming video to a large number of viewers.
Network bandwidth
Bandwidth is the maximum amount of data passing through a network at once. If the amount of data exceeds the bandwidth, it significantly slows down data delivery. A CDN delivers a stream across multiple distributed servers, ensuring that streaming content does not exceed network bandwidth.
Protecting Origin Servers
One of the crucial roles of a video CDN is to protect the origin servers from overload. By distributing the load across multiple servers, CDNs ensure that the stream’s source server is not overwhelmed with requests. This not only ensures smooth streaming for viewers but also safeguards the infrastructure from potential crashes or slowdowns.
Video CDN Providers
There are various video CDN providers available, each with its strengths and weaknesses. Some notable providers include Cloudflare, G-Core CDN, and Hostry Free CDN. When choosing a provider, it’s essential to weigh the benefits against potential disadvantages such as cost, complexity, and control over the CDN settings and configurations.
How Do Video CDNs Work?
A video CDN works by caching video content on servers located at the edge of the network, closer to end-users. This way, when a user requests a video, it can be delivered quickly from the nearest edge server, reducing latency, jitter, and timeouts, and improving the overall user experience.
When a user requests a video, the request is directed to the nearest CDN edge server, which checks if the requested video is already cached on the server. If it is, the video is delivered to the user directly from the edge server. If it’s not, the edge server communicates with the origin server where the video is hosted, retrieves the video, and caches it on the edge server for future requests.
How the CDN provider operates
CDN providers use load balancing and solid-state drives (SSDs) to deliver content quickly and efficiently. Load balancing ensures that traffic is evenly distributed across all available servers, while SSDs provide fast read and write speeds, reducing the time it takes to retrieve and cache videos.
To purchase CDN services, organizations typically sign up with a CDN provider, pay a monthly or yearly fee based on the amount of traffic and data transferred, and configure their website or video platform to use the CDN provider’s network.
CDN providers also use artificial intelligence (AI) and machine learning to accelerate loading time. AI algorithms analyze user behavior and predict which videos are likely to be requested next, enabling edge servers to proactively cache those videos before users even request them, further reducing latency and improving the user experience.
Cloudinary Multi-CDN Solution Auto-Selects Best CDN for Optimal Per-User Experience
From the time of its founding, Cloudinary’s vision has always been to provide a complete image and video management solution, so that developers can forget about these issues and focus exclusively on the product or solution they are developing for their own users.
To that end, Cloudinary offers easy and automated ways to optimize, crop, enhance, overlay, select quality and format, make images responsive, and much more. And since 2012, CDN delivery has also been a part of that solution.
Now, with the option to select the best CDN for each scenario in an automatic and virtually transparent way, Cloudinary has taken another big step towards providing Web and app developers with that complete and total media management solution.
All Cloudinary plans, including the free plan, enable our users to enjoy worldwide CDN delivery.
The smart CDN selection and dynamic multi-CDN switching features described in this post are available to Enterprise-level customers and the dynamic multi-CDN feature affects pricing. These features are currently supported for Akamai, Fastly and CloudFront CDNs. To request implementation of either of these CDN features, or for additional details, contact us today.