How Does Agora’s Network Compare to a Content Delivery Network?
The internet has grown tremendously over the past few decades, becoming an integral part of our daily lives. However, it still faces limitations when meeting the demands of live video and audio streaming. The internet’s best-effort system favors reliability over speed for good reason. But in real-time time communication, you need both speed (or low latency) and reliability, with guaranteed delivery and quality of service (QoS).
The public internet’s lack of real-time speed stems from the path that traffic follows to get to its destination. The flow of public internet traffic follows paths through complex networks, often determined by business agreements between internet service providers and mobile networks, typically prioritizing low cost over high speed. This is a problem that content delivery networks were created to address years ago, but they only work for certain types of content.
Content Delivery Networks
Content delivery networks, or CDNs, use distributed network architecture to address routing challenges for content like webpages, on-demand video, etc. In this setup, CDNs use a global network of servers to “cache” or store content and assets in various locations to shorten the path from the digital content to the end user’s device.
While the CDN model of caching works great for preexisting or prerecorded content, like your favorite Netflix show, it doesn’t work for or real-time communication because the “content” that needs to be delivered can’t be stored on nearby servers in advance. CDNs can be suitable for one-way, one-to-many live streaming scenarios, such as live sports, music, and events, but with a delay (latency) of 1 to 30 seconds. This delay makes real-time communication and interaction impossible.
Agora’s Software Defined-Real Time Network™
To address the specific delivery challenges that come with real-time interaction, Agora built its own network from the ground up. Agora’s Software Defined-Real Time Network™ (SD-RTN™) is set up with global points of presence like a CDN, but instead of caching content, it dynamically selects the most efficient routes for transmitting streams of video and audio frames with the highest speed, or lowest amount of delay (low latency).
This model ensures highest quality experience for users by eliminating any lag or freezes, optimizing for fluency, even under poor local network conditions. Agora’s network works everywhere and isn’t constrained by telecom coverage areas or internet service providers.
Let’s look at the basic operation of a Content Delivery Network (CDN) and how Agora’s SD-RTN™ architecture is similar but distinct.
Comparing Standard CDN to Agora’s Network
Several factors must be considered when comparing a standard Content Delivery Network (CDN) with Agora’s Software-Defined Real-Time Network (SD-RTN). These include their primary use cases, technology, scalability, latency, and reliability.
| Feature | Standard CDN | Agora’s SD-RTN |
|---|---|---|
| Primary Use Case | Delivering static and dynamic “on-demand” content to end-users. | Delivering real-time video and audio streaming and synchronization. |
| Technology | A distributed network of servers to cache content. | Software-defined network optimized for low-latency, real-time communication. |
| Scalability | While CDNs can easily scale to support large audiences for pre-existing or on-demand content, they cannot support real-time content delivery without introducing latency or delay. | Highly scalable for real-time interactions, with dynamic routing to ensure low latency. Agora supports over 1 million concurrent participants in a single large-channel broadcast session. Can quickly add server capacity as needed at local data centers or connect more at the continent level. |
| Latency | Optimized for static content delivery, but not specifically for real-time interaction. | Designed for ultra-low latency with a median global latency <76ms critical for real-time communications versus the ten-plus seconds of some CDN vendors. |
| Reliability | High reliability through redundancy and caching. However, a traditional CDN cannot reroute the connection in case of a local service outage. | High reliability with intelligent routing and real-time monitoring to find the best real-time connection route based on actual network conditions. |
| Content Types | Best for static files (HTML, CSS, JS), video-on demand, and images. | Specialized in interactive live audio and video streaming. |
| Customization | Limited to caching rules and delivery optimization. | High, with options for standardized SDK libraries across all key platforms, compared to fragmented CDN content delivered within various media players for each target platform. |
| Smart monitoring and route optimization | Best efforts and no smart monitoring as standard. | Smart monitoring and route optimization. In the event of a catastrophic outage in a particular regional data center, the network will automatically reroute around the outage. |
Which Network Option Fits Your Use Case?
While both solutions augment user experience through latency reduction and improved content delivery, they diverge significantly in technology, supported use cases, and optimization tactics. Ultimately, CDNs are excellent and economical for static or on-demand content but fall short in delivering real-time experiences due to latency issues. Agora’s SD-RTN provides specialized functionalities for real-time communication, extending well beyond the capabilities of standard CDN services.
Even in use cases of one-to-many live streaming, where a CDN could work with a delay, a real-time network like Agora’s allows for a better viewing experience that’s synced with the real event. This is particularly useful in scenarios like live sports where delays in the live stream often spoil the excitement when viewers are texting with fans at the game or placing sports bets that update scores with much less delay.
For any live digital experience that requires minimal delay, Agora’s SD-RTN is the only global network built and optimized for real-time video and voice interaction.
For more detailed look at Agora’s network in comparison with CDN, check out this whitepaper: Agora’s Software Defined Real-Time Network™ Delivers Real-Time Internet Advantages Over Content Delivery Network
