# Firmware Dependency Reference

New capabilities in the Red Hat single sign-on (SSO) integration are tied to specific Cloud Voice firmware builds. SSO lets a user authenticate once with a central identity provider (Red Hat) instead of maintaining a separate password for the phone system. Before you rely on a feature described elsewhere in this section, confirm that your system is running the firmware version listed below. If your build is older, upgrade first.

:::caution
Upgrading firmware normally restarts the phone system, which can interrupt active and incoming calls (including emergency calls). Schedule the upgrade during a maintenance window and confirm no critical calls are in progress before you begin.
:::

## Version history

| Released | What changed | Minimum firmware |
| --- | --- | --- |
| December 3, 2025 | Introduced control over how Red Hat SSO users authenticate to the Cloud Voice App. Administrators can require single sign-on exclusively, or permit users to sign in either through SSO or with the account credentials tied to their extension. | 84.21.0.66 or later |
| November 10, 2025 | First release of the integration. | 84.21.0.16 or later |

:::note
The firmware version shown is the minimum required for each capability. Running a later build is fully supported and gives you every feature at or below your current version.
:::