---
title: "Concurrent Stream Limiting (CSL)"
slug: "concurrent-stream-limiting-csl"
updated: 2025-10-24T11:03:59Z
published: 2025-10-24T11:03:59Z
canonical: "documentation.deltatre.com/concurrent-stream-limiting-csl"
---

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

# Concurrent Stream Limiting (CSL)

| Mobile | Tablet | Web | TV |
| --- | --- | --- | --- |
| ![android_watermark.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490958972956.svg) | ![iOS.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490959197852.svg) | ![android_watermark.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490958972956.svg) | ![iPadOS.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490914682524.svg) | ![HTML5.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490951859100.svg) | ![android_watermark.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490958972956.svg) | ![tvOS.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/5569247809180.svg) | ![HTML5.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490951859100.svg) | ![Roku.svg](https://cdn.document360.io/2e698e3c-4773-44a4-9476-1d05bac85eee/Images/Documentation/4490959071132.svg) |

## What is Concurrent Stream Limiting (CSL)?

Concurrent Stream Limiting (CSL) is a feature provided by Castlabs to implement concurrent video streaming limitation at the playback level.

### How does CSL work?

DRM licenses have a fixed duration and therefore must be renewed to continue video playback.

The implementation of CSL means we can now control the maximum number of concurrent video sessions started by a user account. In addition, this can help to limit piracy streaming.

Implementing CSL differs depending on client and project needs, please speak to your Product Engagement representative or Project Manager for further information.