note limitations

Author: robswain

articles/private-5g-core/collect-required-information-for-a-site.md

@@ -54,7 +54,11 @@ Collect all the values in the following table for the packet core instance that
 
 ## Collect RADIUS values
 
-If you have a Remote Authentication Dial-In User Service (RADIUS) authentication, authorization and accounting (AAA) server in your network, you can optionally configure the packet core to use it to authenticate UEs on attachment to the network and session establishment. If you want to use RADIUS, collect all the values in the following table.
+If you have a Remote Authentication Dial-In User Service (RADIUS) authentication, authorization and accounting (AAA) server in your network, you can optionally configure the packet core to use it to authenticate UEs on attachment to the network and session establishment.
+
+Your RADIUS server must be on your management network and reachable from your Azure Stack Edge device. RADIUS is only supported for authentication when UEs attach to the network or initiate a session. Other RADIUS features, such as accounting, are not supported.
+
+If you want to use RADIUS, collect all the values in the following table.
 
 |Value  |Field name in Azure portal  |
 |---------|---------|

articles/private-5g-core/security.md

@@ -54,6 +54,8 @@ As these credentials are highly sensitive, Azure Private 5G Core won't allow use
 
 Azure Private 5G Core supports Remote Authentication Dial-In User Service (RADIUS) authentication. You can configure the packet core to contact a RADIUS authentication, authorization and accounting (AAA) server in your network to authenticate UEs on attachment to the network and session establishment. Communication between the packet core and RADIUS server is secured with a certificate stored in Azure Key Vault. The default username and password for UEs are also stored in Azure Key Vault. You can use the UE's International Mobile Subscriber Identity (IMSI) in place of a default username. See [Collect RADIUS values](collect-required-information-for-a-site.md#collect-radius-values) for details.
 
+Your RADIUS server must be reachable from your Azure Stack Edge device on the management network. RADIUS is only supported for initial authentication. Other RADIUS features, such as accounting, are not supported.
+
 ## Access to local monitoring tools
 
 ### Secure connectivity using TLS/SSL certificates