With this option, large files are delivered faster due to multi-threaded uploading to the CDN cache. Files are split into 10 MB parts each and cached into in simultaneous requests. An end user gets the assembled file.
For example, 56 MB file will be divided into 6 parts. Five of them will be 10 MB each and the sixth will be 6 MB. A closest CDN server caches this file using six-threaded download. While the file is being delivered to the user it is assembling from this parts from a cache. Next users get this file from cache.
Please note, this option will be applied to all of your CDN files, so the load on your origin will definitely grow.
Check settings
Your origin should support HTTP Range requests. Run cURL command in the console on your computer or use online services:
curl -I http://cdn.site.com/images/1.jpg
HTTP/1.1 200 OK
Server: nginx/1.11.4
Date: Wed, 05 Apr 2017 19:27:14 GMT
Content-Type: image/jpeg
Content-Length: 62890
Connection: keep-alive
Last-Modified: Mon, 03 Oct 2016 22:21:05 GMT
ETag: "f5aa-53dfd5c25d421"
FILE: Image
Access-Control-Allow-Origin: *
Cache: HIT
X-ID: m9-up-e240
Accept-Ranges: bytes
There should be header Accept-Ranges: bytes in the answer.
If you request certain Range, for example, 2 bytes, origin answer should contain 2 bytes.
curl -s -I -H 'Range: bytes=0-1' http://cdn.site.com/images/1.jpg | egrep 'Length|Range'
Accept-Ranges: bytes
Content-Length: 2
Content-Range: bytes 0-1/10240
Video delivery
Use this option to deliver video on demand in the Progressive Download mode (Pseudo Streaming).
Pseudo Streaming features:
1. Instant replaying without entire video caching (pseudo prefetching).
2. Rewind function imitates streaming. A user can replay video from any point even if the needed part hasn't been downloaded yet to a user's device. Media-player interface requests missing video parts based on metadata contained in the video file.
Unlike streaming mode Internet connection speed doesn't matter for replaying video using pseudo streaming. So it is helpful if your project requires maximum audience including Internet 3G mobile users.