---
title: "Low Latency Live"
slug: "low-latency-live"
updated: 2025-06-08T11:51:48Z
published: 2025-06-08T11:51:48Z
stale: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://docs.qwilt.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Low Latency Live

## Overview

Use the Low Latency Live rule to enable advanced features for the optimized delivery of Low Latency DASH and/or HLS streams. This rule is available for sites configured for the Live traffic type.

          Warning:

          

The Low Latency Live rule is designed to optimize live streams for low-latency delivery, but only works if your entire workflow supports the LL-DASH or LL-HLS streaming protocols. For best results, ensure that both your origin and player are fully configured for one or both of these protocols, as enabling the rule without full end-to-end support for LL-DASH and/or LL-HLS, could degrade performance instead of improving it.

## Configure the Rule

Here, we'll describe how to configure the rule with the Delivery Service Management UI.

API Users may choose to [build the site configuration offline](https://api-docs.qwilt.cqloud.com/docs/CDN%20APIs/Sites%20API/prepare-the-configuration-json).

**To configure a Low Latency Live rule:**

1. Make sure the host is configured for the Live [traffic type](/v1/docs/traffic-type).
2. [Navigate to the Select Rule dialog](/v1/docs/add-a-rule).
3. In the Select Rule dialog, choose **Low Latency Live**.
4. In the Low Latency Live Rule dialog, select the **Low Latency DASH** or **Low Latency HLS** option.

![LLLRuleWithBothOptionsDisplayed.png](https://cdn.document360.io/fa039225-513b-46a1-ba78-a57a1f1cb7c6/Images/Documentation/LLLRuleWithBothOptionsDisplayed.png)
5. Select **Add Rule**.

### Implementing the Low Latency HLS Option

This section provides additional instructions for implementing the Low Latency HLS option.

- **Configure a Cache Key Management Rule** Configure a Cache Key Management rule to ensure the following query parameters are included in the cache key: `_HLS_msn`, `_HLS_part`, and `_HLS_skip`. This is essential for ensuring accurate content delivery in Low Latency HLS streaming.

For example: ![cacheKeyMgtLLLHLS.png](https://cdn.document360.io/fa039225-513b-46a1-ba78-a57a1f1cb7c6/Images/Documentation/cacheKeyMgtLLLHLS.png)

[Learn how to Configure a Cache Key Management rule](/v1/docs/z-cache-key-management)

- **Adjust Origin Read Timeout to Support EXT-X-PRELOAD-HINT** If you are using the LL-HLS protocol's [EXT-X-PRELOAD-HINT](https://developer.apple.com/documentation/http-live-streaming/enabling-low-latency-http-live-streaming-hls#Provide-Preload-Hints-and-Blocking-of-Media-Downloads) functionality, consider adjusting the *Read Timeout* setting in the origin configuration. [Learn how to Configure an Origin](/v1/docs/configure-an-origin)

A client using `EXT-X-PRELOAD-HINT` can anticipate upcoming segments and request them before they are available from the origin. To prevent timeouts when the client requests a segment before it is ready, set the origin read timeout to 1.5 to 2.5 times the segment duration.

For example, if segments are 2-4 seconds long, a suitable Read Timeout value is 6 seconds.

![originReadTimeoutLLL1.png](https://cdn.document360.io/fa039225-513b-46a1-ba78-a57a1f1cb7c6/Images/Documentation/originReadTimeoutLLL1.png)

## SVTA Component: MI.TrafficType

When you save the configuration version, the `hints` array with the `ll-dash` or `ll-hls` value is added to the *MI.TrafficType* SVTA component in the configuration JSON. The hint informs the CDN that the traffic it will handle is streaming video using the Low-Latency DASH or Low-Latency HLS protocol so the CDN can apply protocol-specific optimizations.

The following configuration triggers optimized processing for Low-Latency DASH:

```
{
    "generic-metadata-type": "MI.TrafficType",
    "generic-metadata-value": {
        "traffic-type": "live",
        "hints": [
            "ll-dash"
        ]       
    }
}
```

This is an example of the `MI.TrafficType` component configured to trigger optimized processing for Low-Latency HLS, along with the `MI.Cache` component, as an example of how to set up a Cache Key Management rule to include the required query parameters:

```
{
    "generic-metadata-type": "MI.TrafficType",
    "generic-metadata-value": {
        "traffic-type": "live",
        "hints": [
            "ll-hls"
        ]
    }
},
{
    "generic-metadata-type": "MI.Cache",
    "generic-metadata-value": {
        "exclude-path-pattern": "",
        "include-query-strings": [
            "_HLS_msn",
            "_HLS_skip",
            "_HLS_part"
        ]
    }  
}
```

This is an example of the `MI.TrafficType` component, along with the `MI.ComputedCacheKey` component, as an example of how to set up an advanced Cache Key Management rule to include the required query parameters:

```
{
    "generic-metadata-type": "MI.TrafficType",
    "generic-metadata-value": {
        "traffic-type": "live",
        "hints": [
            "ll-hls"
        ]
    }
},
{
    "generic-metadata-type": "MI.ComputedCacheKey",
    "generic-metadata-value": {
        "expression": "req.uri.path . '&' . '?' . req.uri.querykv._HLS_msn . '&' . req.uri.querykv._HLS_skip . '&' . req.uri.querykv._HLS_part"
    }
}
```