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Documentation Index

Fetch the complete documentation index at: https://gcore.com/docs/llms.txt

Use this file to discover all available pages before exploring further.

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Overview

MPEG-DASH (Dynamic Adaptive Streaming over HTTP) is an HTTP-based adaptive streaming protocol for live and VOD delivery. A DASH stream uses an .mpd manifest and media segments, so it can be cached and delivered through Gcore CDN like other HTTP video formats. Low-Latency MPEG-DASH (LL-DASH) is the low-latency mode for DASH live streaming. It enables 2-4 second glass-to-glass latency with CMAF (Common Media Application Format) segments and Gcore’s Chunked-Proxy technology, which streams content immediately as it’s received instead of waiting for complete file downloads.

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When to use DASH via CDN

Use Video CDN for DASH if:
  • You already have DASH streams (.mpd manifests and media segments)
  • You handle transcoding and packaging on your side
  • You need broad device compatibility for Android, Smart TVs, web browsers, or custom players
  • You want CDN features like geo-blocking, secure tokens, origin shielding, or custom domains
Use LL-DASH if you also need 2-4 second latency for live events such as sports, auctions, gaming, or interactive broadcasts.

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When to use LL-DASH

Use LL-DASH if:
  • You need 2-4 second latency for live events (sports, auctions, gaming)
  • Your transcoder produces MPEG-DASH with CMAF segments
  • You need broad device compatibility (Android, Smart TVs, web browsers)
  • You want an industry-standard alternative to LL-HLS
Use Video Streaming Platform if:

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How LL-DASH works on Gcore CDN

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Traditional CDN delivery (high latency)

Standard CDNs use “Store and Forward” delivery:
  1. The CDN edge waits for the complete segment to download from the origin (2-6 seconds).
  2. Only then starts sending to viewers.
  3. Result: minimum latency of 10–15 seconds.

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Gcore Chunked-Proxy delivery (low latency)

Gcore’s Chunked-Proxy module uses immediate streaming:
  1. The CDN then begins delivering the segment to viewers.
  2. Immediately starts streaming to viewers while still downloading.
  3. Uses HTTP Chunked Transfer Encoding (HTTP/1.1) or Framing (HTTP/2/3).
  4. Result: 2-4 second glass-to-glass latency.
Technical details: Read our engineering blog post: Optimizing HLS and DASH for 3-second latency - essential reading for CTOs and video engineers.

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Requirements

To use DASH via Gcore CDN:
RequirementDetails
Standard DASH formatMPEG-DASH (.mpd manifests and media segments such as .m4s)
LL-DASH formatMPEG-DASH with CMAF segments (.mpd manifests, .m4s segments)
Chunked-Proxy activationRequired only for LL-DASH. Contact Gcore Support
Paid CDN planAny paid subscription
Legal approvalVideo delivery enablement from Gcore Support
Critical: Chunked-Proxy activation is mandatory for LL-DASH low-latency delivery. Without it, DASH delivery works as standard CDN delivery with higher latency, typically 10-15 seconds instead of 2-4 seconds.

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Quick setup

Step-by-step guide: Create a CDN Resource for Video Streaming Select the “For Live MPEG-DASH CMAF Streaming” tab for complete instructions on:
  • Requesting Chunked-Proxy activation from support
  • Configuring cache rules for manifests and segments
  • Enabling “Always online” for reliability
  • Testing your low-latency stream

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Supported file formats

File TypeExtensionDescription
Manifests.mpdDASH Media Presentation Description
Video segments.m4s, .m4vCMAF video segments
Audio segments.m4a, .m4sCMAF audio segments
Initialization.mp4Initialization segments for fMP4 streams

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How Chunked-Proxy works

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Without Chunked-Proxy (standard CDN)

Origin → [CDN waits for full file] → CDN → Viewer
         ⏱️ 2-6 second delay
Total latency: 10-15 seconds

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With Chunked-Proxy (Gcore CDN)

Origin → [CDN streams immediately] → Viewer
         ⚡ No waiting
Total latency: 2-4 seconds
Key technical advantages:
  • Byte-level streaming: Data flows from origin → CDN → viewer simultaneously
  • Protocol optimization: HTTP/1.1 Chunked Transfer Encoding, HTTP/2 Framing
  • RAM-based caching: LIVE STREAMING preset uses RAM instead of disk
  • Origin shielding compatible: Reduces origin load while maintaining low latency

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Activation process

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Step 1: Request Chunked-Proxy activation

Contact Gcore Support with:
  • Your CDN resource ID or domain
  • Confirmation you’re using LL-DASH with CMAF segments
  • Your origin transcoder details (Wowza, Nginx-RTMP, FFmpeg, etc.)
Processing time: Usually 1-2 business days
Using Gcore Video Streaming? If you’re using our Video Streaming Platform with transcoding, Chunked-Proxy is already enabled by default. No activation needed.

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Step 2: Configure CDN resource

After activation, follow the cache configuration steps in the Getting Started Guide. Key settings:
  • Manifests (.mpd): 2 second cache
  • Segments (.m4s): 60 second cache
  • Always online: Enabled (error + timeout, not updating)
  • LIVE STREAMING preset: Enabled for RAM caching

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Best practices

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Origin configuration

  • Segment duration: 2-6 seconds (shorter = lower latency, higher overhead)
  • Chunked encoding: Enable chunked transfer encoding on your origin
  • Availability window: Keep 30-60 seconds of segments available

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CDN optimization

  • Origin shielding: Recommended for 100+ concurrent viewers
  • Edge locations: Content cached at 210+ global edge servers
  • Monitoring: Use CDN Statistics to track performance

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Player compatibility

Ensure your video player supports:
  • MPEG-DASH playback
  • CMAF segment format
  • Low-latency mode (if available)
Recommended players:
  • dash.js (with low-latency mode)
  • Shaka Player
  • ExoPlayer (Android)
  • AVPlayer (iOS/tvOS with DASH support)

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Latency comparison

Delivery MethodTypical LatencyUse Case
LL-DASH (Gcore Chunked-Proxy)2-4 secondsLive sports, auctions, interactive events
Standard DASH (no Chunked-Proxy)10-15 secondsNews, conferences, less interactive content
HTTP-FLV1-3 secondsUltra-low latency for specific use cases
Traditional RTMP3-5 secondsLegacy systems

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Technical deep dive

For video engineers and CTOs interested in the technical implementation: Engineering blog post: Optimizing HLS and DASH for 3-second latency This article covers:
  • HTTP Chunked Transfer Encoding implementation
  • HTTP/2 and HTTP/3 framing optimizations
  • Origin-to-edge-to-viewer data flow
  • Benchmarks and performance analysis
  • Comparison with other low-latency approaches

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Troubleshooting

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High latency (>10 seconds)

Cause: Chunked-Proxy not activated or not working correctly Solution:
  1. Verify Chunked-Proxy is activated by support
  2. Check origin supports chunked encoding
  3. Verify CMAF segments are used (not MPEG-TS)
  4. Contact Gcore Support for diagnostics

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Buffering or playback issues

Cause: Cache settings too aggressive or manifest updates too slow Solution:
  1. Reduce manifest cache to 1-2 seconds
  2. Ensure segment cache is 60 seconds
  3. Enable “Always online” (error + timeout only)
  4. Check origin availability and response times

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Need help?

Contact Gcore Support or use the chat in the bottom-right corner.

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Next steps

Getting Started Guide

Complete setup instructions to create a CDN resource for video streaming

HLS and LL-HLS

Alternative HLS formats for standard and low-latency streaming

Video CDN Overview

All Video CDN features and capabilities

Engineering Blog

Technical deep dive: 3-second latency optimization