To deliver content as quickly as possible, many organizations use a content delivery network (CDN). However, single CDNs have limitations, like outage risks. To overcome these limitations, many organizations adopt a multi-CDN strategy to optimize content delivery and enhance overall performance.

A Multi-CDN architecture distributes content across various networks so that businesses can deliver content efficiently, regardless of geographic location or network conditions. By creating a network of CDNs, organizations improve reliability, expand reach, and enhance streaming quality. By understanding the benefits of a multi-CDN strategy, organizations can achieve seamless content delivery to optimize costs and enhance user experiences.
 

What Is Multi CDN? 

A multi-CDN architecture uses multiple CDN providers simultaneously to deliver content to users. This strategy enhances reliability and minimizes the risk of downtime that can occur with a single provider.
At a high level, a multi-CDN strategy enables organizations to: 

• Improve performance: evaluating and selecting the best CDN for specific conditions to optimize performance and ensure content delivery with the lowest latency. 
• Save money: utilizing multiple CDNs to lower costs, especially since even an hour of downtime may lead to significant financial losses. 
• Offer broader coverage: combining resources of different providers for better coverage and reliable delivery across diverse geographic regions. 
• Enhance user experiences: leveraging real-time data to route traffic efficiently, ensuring faster load times and optimal performance. 

CDN vs. Multi CDN: What Is the Difference? 

The easy answer to this question is that one strategy uses a single CDN provider, and the other has more than one. While true, this statement ignores the primary value of having more than one CDN. The primary difference between the strategies lies in how they enable the organization to ensure speed and reliability. Typically, organizations choose a multi-CDN for three main reasons:  

• Redundancy: In a multi-CDN architecture, the organization has backup providers if one experiences an outage. With a single CDN, the organization relies on the single provider’s backup capabilities.  
• Performance: In a multi-CDN architecture, the organization can achieve optimal performance because it can leverage the different benefits of each provider. A single CDN relies on one provider’s capabilities.  
• Downtime impact: In a multi-CDN architecture, the organization minimizes the impact of downtime with the ability to offload traffic to another provider. With a single CDN, the organization may face a severe impact from an outage at the provider. 

Why Use a Multi-CDN Architecture?  

A multi-CDN architecture combines the resources of different CDN providers to achieve more reliable service if one provider experiences an issue. The approach increases Points of Presence (PoPs), improving coverage and performance.  

Improved Video Quality 

With more PoPs, a multi-CDN architecture enhances video quality by reducing the distance signals must travel, decreasing buffering and lag. This leads to smoother viewing, especially for live streams requiring real-time engagement. By using advanced algorithms, multi-CDNs improve in-stream switching and Quality of Experience (QoE) metrics that allow for consistent, high-quality playback, even in variable network conditions.
 

Reliable Delivery 

A primary fallback scheme within a multi-CDN setup ensures reliability by designating a main provider and using others for fallback during outages. Multi-authoritative DNS options enhance backup security, guarding against disruptions. Providers that focus on optimizing web performance across diverse geographic regions help maintain reliability even in areas with strict regulations. With a 24/7 monitoring service that addresses any security concerns and promises uninterrupted content delivery, organizations create a strategy that prevents vendor lock-in, offering a range of delivery options. 

Increased Capacity 

Multi-CDNs enable content distribution across a greater number of servers, boosting capacity for more viewers. Enhanced server distribution means broadcasts can reach more people without sacrificing performance. This architecture mitigates traffic congestion, efficiently managing spikes by routing web traffic smartly. By leveraging multiple infrastructures, broadcasters can effectively optimize bandwidth for high-volume streaming. 

Best Practices for Implementing a Multi-CDN

Choosing the right approach for a Multi-CDN strategy can greatly improve an organization’s content delivery.  

Pick and Configure CDNs 

When evaluating various CDN providers, organizations should consider the following: 

• Geographic coverage  
• Performance  
• Server infrastructure 
• Scalability 
• Pricing model 
• Features 
• Support services 

To find the best match, organizations may want to conduct A/B testing between several providers.  

Determine Implementation Method 

When implementing multi-CDN, organizations can choose between three typical approaches: 

• DNS load balancing: By using DNS load balancing to select the appropriate CDN for a given location, the organization can implement a multi-CDN rapidly without a complex network infrastructure, leverage real-time performance data when making decisions, and scale to meet changing delivery needs.  
• Primary-fallback: By designating a primary CDN provider and using others as fallback provider, the organization can easily create a reliable content delivery architecture without a complex network infrastructure, but the configuration may provide suboptimal performance for certain locations or user groups.  
• Performance data-driven load balancing: By using real-time performance data to determine the best content delivery provider for a location, the organization creates a flexible architecture that optimizes performance, even if it requires building a complex network architecture that requires specialized skills, hardware, or software. 

Implement Traffic Management Tools 

Traffic management tools are vital in a Multi-CDN setup because they help distribute and optimize content based on real-time data. Many organizations choose to use a managed DNS provider to manage traffic and any transitions to the new architecture. In a multi-CDN setup, organizations can leverage a DNS provider’s geolocation routing to improve performance by choosing the closest CDN. 
Learn more about how UltraDNS distributes and optimizes content with Directional DNS.

Monitor and Optimize Performance and Availability 

To ensure optimal performance and availability, organizations should establish, monitor, and track key performance indicators, like: 

• Time to First Byte (TTFB): latency indicator measuring the time from a user’s request to the first byte of data they receive  
• Throughput: data transfer rates during peak usage, measured in megabytes per second (Mbps) or gigabytes per second (Gbps) 
• Error rate: indicating configuration issues or capacity limitations 
• Geographic performance: insights into variations across different regions, potentially indicating the need for additional PoP or optimization strategies 

Implement Failover and Redundancy Mechanisms 

A multi-CDN setup enhances network redundancy by allowing traffic to reroute during outages, ensuring content remains available. Any multi-CDN architecture should support up to 99.999% availability, reducing the impact of failures. By dynamically adapting to location and provider status, this strategy ensures reliable and consistent content delivery, even during peak times.
Discover how UltraDNS optimizes traffic using advanced traffic direction.

UltraDNS: Multi-CDN Management to Maximize Uptime and Performance 

UltraDNS uses a robust network of monitoring nodes and real user data to automate routing and identify the fastest provider in each region. The UltraDNS Multi-CDN strategy reduces latency, improves performance, and reduces cost by intelligently routing traffic in real-time to the CDN provider offering the most optimal performance. 
Instead of using a CDN aggregator or third-party provider, we automatically update your DNS records to point to the fastest one for huge performance gains, even when CDNs share the same PoPs. Our CDN load-balancing services include built-in failover and outage recovery so that you can seamlessly migrate traffic to backup providers to prevent downtime and reduce business interruption. With our global GeoDNS capabilities, you can build your own custom configurations or use our traffic steering capability to dynamically route users to the fastest servers in their region or for their specific location or network.


UltraDNS supports real-time decisions with automation, enabling organizations to understand modern traffic logic. Our ability to work across small—and large-scale deployments without hiring a CDN or network specialist means you can scale your multi-CDN in alignment with your enterprise growth path by leveraging our advanced DNSSEC and analytics capabilities.