Skip to main content

Query String Forwarding: forward parameters to sub-requests

Overview

Query String Forwarding copies selected query string parameters from a parent file request to nested file requests. It is mainly used for HLS and MPEG-DASH video, where a viewer requests a master manifest first, and that manifest references rendition manifests, media segments, subtitles, or other related files.

For example, a viewer can request a protected HLS master manifest with a secure token:

http://demo-files-protected.gvideo.io/coffee_run/master.m3u8?expires=1893456000&md5=eBx15p01_a9JNuo1iZpTfQ

Without this option, nested manifests and segments in the manifest body are transferred as is, meaning they don't have query string parameters:

manifest.m3u8?expires=1893456000&md5=eBx15p01_a9JNuo1iZpTfQ
index720.m3u8                 <= as is, without token parameters
chunk720-1.ts                 <= as is, without token parameters

When Query String Forwarding is enabled, the CDN automatically inserts the parameters from the initial request into nested manifests and segments. For example, for Secure Token, the md5 and expires parameters are forwarded:

manifest.m3u8?expires=1893456000&md5=eBx15p01_a9JNuo1iZpTfQ
index720.m3u8?expires=1893456000&md5=eBx15p01_a9JNuo1iZpTfQ
chunk720-1.ts?expires=1893456000&md5=eBx15p01_a9JNuo1iZpTfQ

Example with enabled Query String Forwarding:

Example of query string forwarding settings

A video player requests only the main manifest and receives a modified version with security parameters already included in all internal links:

Query string parameters are inserted into manifest body links automatically

As the result, the video player doesn't need to operate with tokens for each file, as it reads data from modified manifests instead.

Query string parameters are forwarded from the master manifest to nested manifests and segments

Configure in the Customer Portal

To configure Query String Forwarding in the CDB Technical Web Portal:

  1. Go to CDN and select the CDN resource you want to configure.
  2. In the sidebar, under the Content section, click Query String Forwarding.
CDN Query String Forwarding settings

  1. Enable the option.

  2. Apply settings (example for HLS/DASH video):

    • Forward from file types: add m3u8, mpd, or any others.
    • Forward to file types: add ts, mp4, m3u8, m4s, vtt, or any others.
    • Forward only keys: add md5, expires, or any others.

  3. Save the CDN resource.

Configure by API

Use the same values when updating a CDN resource by API.

Use these links to check how Query String Forwarding work with a real ABR stream:

Links to demo files are valid until January 1, 2030.

For video-specific setup, recommended file types, and Secure Token path rules, see Secure token for video.