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Intro to Multi-CDN Switching for Video Streaming: Everything You Need to Know 

by | Oct 19, 2023 | CDN

As the demand for smoother and flawless streaming experience grows, video service providers, large and small, are exploring efficient ways to deliver content efficiently and with a better quality. One of the strategies that has emerged as a game-changer is the use of multiple content delivery network (CDN) providers simultaneously, known as multi-CDN strategy.

Through this guide, you’ll be taken on an informative journey on everything you need to know about multi-CDN switching for video streaming, from the core reasons for implementing it to the methods involved and how to choose the best CDN provider thoughtfully.


Understanding CDNs and multi-CDN

First things first: what is multi-CDN switching for video streaming? A CDN, or Content Delivery Network, is a group of interconnected, geographically distributed servers designed to deliver digital content at speed to users based on their locations. For video content providers, reliance on a CDN means hosting your content closer to your users hence ensuring fast, efficient, and reliable content delivery. 

As the name indicates, Multi-CDN or M-CDN is the strategy of using more than one CDN at the same time. Content providers get to increase their reach to varying geographic regions while having several options within a given region. This strategy allows for the smooth switching from one CDN to another based on specific business and audience needs, a process known as multi-CDN switching or multi-CDN load balancing. 


Why your streaming business needs a multi-CDN strategy

Having a multi-CDN strategy has numerous benefits for video streaming businesses. These include preventing outages (which in turn reduce churn), reducing congestion and network bottlenecks, facilitating global product strategies, and offering flexibility in distribution according to specific needs and budgets.

Relying on a single CDN can lead to major service outages. This risk is reduced by a multi-CDN strategy as it offers backup options, allowing for a swift switch to a fully operational CDN in case of any failure.

In terms of global reach, different CDN providers perform with varying levels of reliability and coverage in different geographic regions. A multi-CDN strategy allows you to choose the most suitable CDN for each area, ensuring a consistent product experience irrespective of location.

Finally, collaborating with numerous CDN providers grants you the luxury of selecting the provider that best aligns with your platform’s specific objectives. This flexibility is critical in an industry where every interaction with the audience and each financial resource matters.


Multi-CDN switching Methods

Multi-CDN switching methods define how and when a specific Content Delivery Network is selected for delivering a video stream to a user. Selecting the optimal CDN can be based on several pre-defined rules including cost, video bitrate, and user type, and can be achieved at different stages of a video play. The main methods of multi-CDN switching are on-start CDN selection, mid-stream CDN switching, DNS-based, API-based, active switching, and HTTP redirect.

On-start CDN selection is chosen at the beginning of the stream, with two main methods; DNS-based and API-based. DNS-based CDN selection uses the Domain Name System to redirect traffic to one CDN or another, while the API-based method connects with the CDN selection system via an API to determine what CDN to use. Mid-stream CDN switching divides the video file into video segments which may be served by different CDNs. The techniques for implementing mid-stream switching include active switching, where a video player plugin detects CDN failures and switches CDNs, and HTTP redirect, which redirects each video segment via an HTTP 302 redirect.

Each method has its benefits and drawbacks, including ease of implementation, flexibility, robustness, and possible points of failure. You can learn more about it here.


How to choose the right CDN provider

Streamlining multi-CDN usage for video streaming services begins with identifying the most appropriate CDN providers. They must offer desirable regional coverage and possess an evenly distributed set of strengths and weaknesses. The selection process is key in ensuring the successful implementation of a smart multi-CDN.

Setting a performance threshold and business requirements is the next crucial step. This involves specifying values for metrics such as response time, availability, and throughput. These thresholds and requirements must be in line with the video streaming service’s performance standards as well as its business expectations.



Implementing smart multi-CDN switching for video

Finally, video streaming services need to choose a smart multi-CDN solution like NPAW’s CDN Balancer. Such solutions collect real-time metrics about the performance of different CDN providers and alternate between them as needed, based on established thresholds and business rules. 

To maximize a multi-CDN configuration, it is advisable to invest in a smart multi-CDN switching solution. This follows four major steps:

Accurately identifying traffic and end-user information: This is the foundational step, as accurate traffic data is needed for correct switching decisions.

Leveraging real-time quality of experience insights: Quality data significantly enhances the precision of your CDN switching.

Applying complex QoE-based business rules with precision: Clear-cut, precise rules that take all identified network segments into account ensures smart multi-CDN switching. 

Avoiding a single point of failure with various balancing methods: A competent multi-CDN switching system should offer different CDN switching options to ensure seamless content distribution.

Once chosen, it’s paramount to test the solution extensively before deploying to a production environment. It’s advisable to trial the solution with a fraction of users prior to full deployment. You can learn more here.