What is a Mainland China ICP-free CDN?

A Mainland China ICP-free CDN means a content delivery network that is not filing for an ICP license in China because it has its servers located outside of Mainland China, therefore users in China can access websites fast without an ICP filing. 
How It Works? 
Methods for achieving this are two: 
Shared Domain or IP – The CDN provider takes the responsibility for registering and filing with China’s MIIT one main domain or a subdomain. When users set up CNAME records, all the traffic looks like it comes from the provider’s filed domain, thus bypassing the need for ICP filing. 

Intelligent DNS Routing – The smart DNS of the CDN directs the traffic from Mainland to the nodes, which are already filed and thus located in China, consequently the non-filed projects can be accelerated.

Advantages

Every internet project hosted in Mainland China must go through ICP registration, which usually takes 10–30 days, so an ICP-free CDN provides a faster and easier start without any bureaucratic delays. 
Developers also get the liberty to host their servers anywhere globally and at the same time be able to circumvent the restrictive domestic hosting policies (for instance, in Mainland China, if your ICP is filed at a certain provider, you have to buy servers from that same provider). 

Disadvantages

A significant percentage of the ICP-free CDNs are using nodes in Hong Kong, which, due to their distance, can be not as fast as those in the Mainland. 
Some providers “borrow” filed nodes in Mainland; however, these are limited resources that come with risks — in case another user runs gray-area content, your service may also be disrupted or you may receive block notices. 
Best Solution 
The perfect strategy is to leverage Hong Kong CDN nodes of great quality that are linked to Mainland China with CN2 GIA premium routes and intelligent DNS routing. 
 

Once you turn on edge caching and efficient compression, you are reducing the latency and release the server load from your origin server.

At the moment, Hong Kong CDN by CDN5 is performing at its best in the entire industry in terms of bandwidth capacity and infrastructure, hence, it is the first choice when it comes to Mainland ICP-free acceleration solutions.