Long-distance and cross-border data transmission frequently causes slow access or inaccessibility. This topic describes four methods for accelerating long-distance data transmission using Alibaba Cloud CDN, DCDN (Dynamic CDN), Global Accelerator (GA), and Object Storage Service (OSS).
When to use this
These methods apply when:
Users in a distant region experience slow downloads from your OSS buckets or CDN-accelerated domains.
Uploads from geographically remote clients are too slow to meet your requirements.
Cross-border back-to-origin requests between a CDN point of presence (POP) and your origin server add unacceptable latency.
Choose a method
Select the method that matches your scenario:
| Method | Best for | Key mechanism |
|---|---|---|
| CDN/DCDN prefetch | Static content with predictable access patterns | Cache resources at POPs in advance to eliminate back-to-origin latency |
| Dual origin servers | Existing deployments split between the Chinese mainland and other regions | Route each POP to the geographically nearest origin server |
| Global Accelerator | Latency-sensitive applications with dynamic or non-cacheable content | Deliver traffic using intelligent routing to improve access speed and efficiency |
| OSS transfer acceleration + CDN | Origin services that can be migrated to OSS | Combine OSS transfer acceleration with CDN to accelerate data transmission |
OSS transfer acceleration and CDN/DCDN address long-distance transmission in different ways. For a comparison, see Differences between Alibaba Cloud Content Delivery Network acceleration and OSS transfer acceleration.
Method 1: Prefetch resources to CDN or DCDN POPs
Alibaba Cloud CDN accelerates content delivery by serving requests from a POP cache. When a POP has no cached copy, it retrieves the resource from the origin server — a back-to-origin request that crosses the long-distance network path you are trying to avoid.
Prefetching pushes resources to POPs before users request them. Clients then retrieve the cached resource directly from the nearest POP without triggering a back-to-origin request.
Use Alibaba Cloud CDN or DCDN to prefetch the resources that users will access. For instructions, see Purge and prefetch resources.
Method 2: Configure dual origin servers with DCDN
If your infrastructure already spans two regions — one origin server in the Chinese mainland and one outside — configure DCDN to route each POP to its nearest origin server during back-to-origin.
Configure the HOST information in HTTP request headers to specify which origin server DCDN contacts. DCDN then selects the corresponding origin server based on the HOST value:
POPs in the Chinese mainland connect to the origin server in the Chinese mainland.
POPs outside the Chinese mainland connect to the origin server outside the Chinese mainland.
When multiple origin servers share the same priority, DCDN distributes requests based on the configured weights, providing load balancing across origin servers.
For configuration details, see Configure an origin server.
Method 3: Use Global Accelerator
Global Accelerator (GA) delivers network access requests from clients to endpoints using intelligent routing to improve access speed and efficiency.
For setup instructions, see Get started with GA.
Method 4: Migrate to OSS and enable transfer acceleration
If your origin service can be migrated to OSS, you can redirect requests to OSS using Alibaba Cloud CDN or DCDN and use the transfer acceleration feature of OSS to accelerate data transmission.
Steps
Migrate your origin service to OSS. For more information, see Overview.
Enable transfer acceleration for your OSS bucket. For more information, see Enable transfer acceleration.
Add an accelerated domain name:
For Alibaba Cloud CDN, see Add a domain name.
For DCDN, see Add a domain name.
Set the back-to-origin host to the OSS acceleration endpoint. For more information, see Configure the default origin host.