Update mqtt-client-authentication.md

Doc Updates - Custom Jwt Authentication Doc

Author: Connected-Seth

articles/event-grid/mqtt-client-authentication.md

@@ -2,9 +2,9 @@
 title: 'Azure Event Grid Namespace MQTT client authentication'
 description: 'Describes how MQTT clients are authenticated and mTLS connection is established when a client connects to Azure Event Grid’s MQTT broker feature.'
 ms.topic: concept-article
-ms.date: 01/21/2025
-author: george-guirguis
-ms.author: geguirgu
+ms.date: 01/27/2025
+author: george-guirguis, seth-shanmugam
+ms.author: geguirgu, seshanmugam
 ms.subservice: mqtt
 # Customer intent: I want to learn about different types of authentication that MQTT broker in Azure Event Grid supports. 
 ---
@@ -14,15 +14,20 @@ ms.subservice: mqtt
 Azure Event Grid's MQTT broker supports the following authentication modes. 
 
 - Certificate-based authentication
-- Microsoft Entra ID authentication 
+- Microsoft Entra ID authentication
+- Custom JWT authentication
 
 ## Certificate-based authentication
 You can use Certificate Authority (CA) signed certificates or self-signed certificates to authenticate clients. For more information, see [MQTT Client authentication using certificates](mqtt-client-certificate-authentication.md).
 
 ## Microsoft Entra ID authentication
 You can authenticate MQTT clients with Microsoft Entra JWT to connect to Event Grid namespace. You can use Azure role-based access control (Azure RBAC) to enable MQTT clients, with Microsoft Entra identity, to publish or subscribe access to specific topic spaces. For more information, see [Microsoft Entra JWT authentication and Azure RBAC authorization to publish or subscribe MQTT messages](mqtt-client-microsoft-entra-token-and-rbac.md). 
 
+## Custom JWT authentication
+You can authenticate MQTT clients  using JSON Web Tokens (JWT) issued by any third-party OpenID Connect (OIDC) identity provider. This authentication method provides a lightweight, secure, and flexible option for MQTT clients that are not provisioned in Azure.For more information, see [authenticate client using custom JWT](mqtt-client-custom-jwt.md)
+
 ## Related content
 - Learn how to [authenticate clients using certificate chain](mqtt-certificate-chain-client-authentication.md)
 - Learn how to [authenticate client using Microsoft Entra ID token](mqtt-client-azure-ad-token-and-rbac.md)
+- Learn how to [authenticate client using custom JWT](mqtt-client-custom-jwt.md)
 - See [Transport layer security with MQTT broker](mqtt-transport-layer-security-flow.md)