Azure Communication Services: Authentication docs need more detail

[sam-byng]

Suggestion: Update the communication services authentication document to make it clearer that other services can use managed identity for authentication.

The following documents do not make it clear that other Azure services can, in fact, authenticate to ACS using AAD managed identity and the 'Contributor' role. This is for use with the SmsClient and the Call Automation client.

• Use Azure Active Directory in Communication Services
• https://learn.microsoft.com/en-us/azure/communication-services/concepts/authentication#azure-ad-authentication

Fix:

• Include the Call automation SDK in the list at Authenticate to Azure Communication Services, and clarify whether this is the same / different to 'Phone Numbers' item. This is confusing since the 'Phone calling' side tab goes to 'Call Automation SDK'
• Add a instruction set for setting up managed identity auth from an Azure App Service, and accessing through C# .NET code using a DefaultAzureCredential . Similar to the Cosmos DB case https://learn.microsoft.com/en-us/azure/cosmos-db/managed-identity-based-authentication

e.g. Add 'Contributor' role for your app service over the ACS instance . Update code: _callAutomationClient = new CallAutomationClient(new Uri(), new DefaultAzureCredential());

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Document Details

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• ID: cd1c1d72-779b-1776-887b-efefdfa15a03
• Version Independent ID: 54a9dfce-6933-ede9-3e35-ae70a416725a
• Content: Authenticate to Azure Communication Services - An Azure Communication Services concept document
• Content Source: articles/communication-services/concepts/authentication.md
• Service: azure-communication-services
• Sub-service: identity
• GitHub Login: @tophpalmer
• Microsoft Alias: chpalm

[SaibabaBalapur-MSFT]

@sam-byng Thanks for your feedback! We will investigate and update as appropriate.

[RyanHill-MSFT]

Hi @sam-byng, I have assigned the issue to the content author to investigate further and update the document as appropriate.

[fowl2]

looks like this has been further discussed here: https://github.com/MicrosoftDocs/azure-docs/issues/109461