Multi-CDN and Dynamic Site Acceleration (DSA) are both strategies to make content delivery faster and more reliable. They are often mentioned together, but they tackle different parts of the problem. Multi-CDN chooses between providers, while DSA focuses on optimizing the transport path between the CDN edge and the origin.

What DSA Does

Dynamic Site Acceleration was introduced in the 2000s as a premium CDN feature. It targets dynamic content that cannot be cached. Instead of improving speed through storage at the edge, DSA makes the path between the edge and the origin faster.

It does this with techniques such as persistent TCP and TLS connections, route optimization over private backbones, protocol upgrades like HTTP/2, and in some cases prefetching or compression. The goal is to reduce latency for every request that must travel back to the origin.

What Multi-CDN Does

Multi-CDN is about redundancy and reach. Instead of relying on a single provider, traffic is routed across several CDN networks. This can be based on geography, performance data, or failover rules. A user in Germany may be served by one provider, while a user in Brazil gets traffic from another. If one network has an outage, traffic can be shifted to the next.

Multi-CDN does not change how the origin itself is accessed. Each provider still connects back to the origin, unless additional optimizations such as caching layers or origin shields are used.

Where They Overlap

Both aim to improve performance and resilience, but they do so at different layers. They may even complement each other. A business might run a Multi-CDN strategy and also enable DSA on one or more of those providers. For example, Multi-CDN ensures a user always hits a fast provider, while DSA improves the transport between that provider’s edge and the origin.

Key Differences

  • Scope: DSA optimizes the edge-to-origin path; Multi-CDN manages provider-to-user distribution.
  • Approach: DSA uses protocol and routing tweaks; Multi-CDN uses traffic steering and redundancy.
  • Use cases: DSA helps when dynamic content dominates and the origin is distant. Multi-CDN helps when global reach and resilience are the priority.

Choosing Between Them

The choice depends on the problem being solved. If users complain about slow dynamic pages due to long origin trips, DSA may help. If outages or uneven performance across regions are the main concern, Multi-CDN is usually the better fit. In some architectures both appear side by side, but in practice Multi-CDN has remained the more visible of the two, while many DSA techniques have been folded into standard CDN features.

For more background on each, see Dynamic Site Acceleration (DSA) and Multi-CDN.