Benefits of CDNs for Live streaming (and What to Look for When Choosing One).

As we discussed before, CDNs are essential for global media streaming. But as a quick reminder, a CDN (Content Delivery Network) is a network of interconnected servers that cache and deliver content. These servers are physically placed at different geographical locations to lower latency and improve responsiveness. While our previous piece discussed the use of CDNs for general media streaming, here we’ll discuss how they improve live streaming in particular. We’ll also explain what to look out for when considering a CDN service for your own live streaming needs.

How does a CDN work for live streaming?

When streaming VOD (Video on Demand), such as in Netflix or YouTube, the video file chunks are stored on host servers. These are then then sent to a CDN to be cached. The CDN servers then deliver the video pieces to viewers when requested. The difference when it comes to live streaming is that there are no existing video files. Instead, the video pieces are cached by the CDN in real time as they are transmitted from the source. The source in this scenario is the streaming setup such as camera(s), microphone(s), encoding and transmission machine(s), etc. These pieces of video are then delivered to audiences geographically close to each server of the CDN on-the-fly as they keep on caching new pieces.

The benefits of using a CDN for live streaming.

Using a CDN for your live stream can have a number of major benefits. These mostly stem from the geographically decentralisednature of CDNs. They include:

Network Strength

CDNs distribute your stream across a widely spread-out network of servers. This means that the only load on your source network is the transmission to the CDN while its handles delivery through its own network. This ensures that your network infrastructure will not be overwhelmed even when streaming globally to a large audience of viewers.

Speed

CDNs essentially create a superhighway for your live streams and live events. The distributed network of servers slashes the time it takes for streams to reach audiences. Content is quickly delivered to servers on the edges of the network, and from there to local viewers and attendees.

Stream Quality

The distributed nature of CDN servers make live streams and online events very resistant against DDoS attacks. DDoS, or Distributed Denial of Service attacks are a common form of cyber-attack. In such attacks, a site, server, stream, or any other online resource is flooded with multiple simultaneous connection requests to overwhelm it and its network infrastructure. However, CDN servers from an interconnected network. Even if one server or multiple servers are targeted with a DDoS attack, live stream traffic can simply be redirected to the next-closest servers to audiences. This gives an additional layer of cyber security to your live streams and online live events. The same network structure also proves a measure of robustness to hardware or network failures. Redundancy in the CDN ensures that your live streams reach global audiences regardless of local network or hardware situations.

Scalability

CDNs are very flexible in their architecture. They can be scaled up or scaled down based on audience size and geographical spread. They can also handle wide variations in viewership. CDNs can be especially flexible in the case of sudden viral popularity, or larger than expected turnout for live events.

Increased Security and Robustness

The distributed nature of CDN servers make live streams and online events very resistant against DDoS attacks. DDoS, or Distributed Denial of Service attacks are a common form of cyber-attack. In such attacks, a site, server, stream, or any other online resource is flooded with multiple simultaneous connection requests to overwhelm it and its network infrastructure. However, CDN servers from an interconnected network. Even if one server or multiple servers are targeted with a DDoS attack, live stream traffic can simply be redirected to the next-closest servers to audiences. This gives an additional layer of cyber security to your live streams and online live events. The same network structure also proves a measure of robustness to hardware or network failures. Redundancy in the CDN ensures that your live streams reach global audiences regardless of local network or hardware situations.

Affordable Infrastructure

Although some mega corporations like Netflix or YouTube choose to build out their own global CDNs, most entities opt to integrate solutions or subscribe to services from CDN providers. These providers maintain their own servers and network infrastructure across the world. This means that you can choose the solution that fits your needs to get the benefits of CDNs without having to make massive investments.

How to choose a CDN for live video streaming.

When choosing a CDN for live streaming, it goes beyond explanation that you need to choose one that has live streaming support. However, there are a number of other factors you need to pay attention to beyond just that. Here are 4 factors you should keep in mind when choosing a CDN for your live streams and online live events.

1. Location Coverage

This is arguably the important factor to consider when choosing a CDN provider. You want a CDN that has servers closest to your audiences. You also want one that actually has coverage in the regions where your target audience is located. If your stream targets Europeans, there’s obviously no point in getting a CDN that only covers South America. At the same time, you also want a CDN with an ingest point close to your stream source (such as your studio or live event venue). Every CDN provider has coverage maps available. Pay attention to the network coverage and overall network structure. You want to ensure that your CDN maximises your stream’s delivery efficiency.

2. Feature Set

You want to choose a CDN that has support for your desired features. Whether it’s adaptive bitrate streaming, content protection features like DRM, or support for your desired streaming protocols (HLS, MPEG-DASH, RTMP, etc) - do your due diligence. Not every provider will support every possible feature, so pay attention in choosing one that supports what you need. Your live stream or online live event will have its own unique requirements. Choose a CDN accordingly.

3. Integrated Solutions vs 3rd Party

CDN providers come as both integrated solution providers, as well as third party services. Some services integrate their CDN services seamlessly into your existing live streaming infrastructure. This allows for quicker deployment and often deeper analytics of how your stream performs. Other providers also offer access to CDNs as a third-party service. These come with a lower need for commitment on your end, but also offer less control and fewer insights. Which one to choose largely boils down to the nature of your operations. If your organisation regularly live streams or hosts live online events, it’s best to get an integrated solution. Integrated solutions will offer a lot of value for such organizations. However, if live streams and events are a rare occurrence for your company, a third-party solution might make a lot more sense.

4. Pricing and Cost-Efficiency

Pricing can also be an important factor based on the scope of your operations and your budget. Pricing structures vary based on the type of provider. Third-party service providers generally charge on a cost per gigabyte basis. Those providing integrated solutions on the other hand may charge an overall fee, or even do custom pricing. You also want take into account your existing backend structure. If you are already running your live streaming server on the cloud on AWS or Azure, you may want to consider their CDN options to gain cost efficiencies. In conclusions, CDNs can provide excellent improvements to your live streaming operations and online live events. Increased stream quality, better user experience, and improved reliability are just some of the benefits to be had. However, when choosing the right CDN, pay attention to the factors that have the most impact for your needs. And stay tuned to our blog to learn more about other streaming technologies!

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