Failed to create CallAgent
In order to make or receive a call, a user needs a call agent (CallAgent).
To create a call agent, the application needs a valid ACS communication token credential. With the token, the application invokes CallClient.createCallAgent API to create an instance of CallAgent.
It's important to note that multiple call agents aren't currently supported in one CallClient object.
How to detect errors
The CallClient.createCallAgent API throws an error if SDK detects an error when creating a call agent.
The possible error code/subcode are
| Code | Subcode | Message | Error category |
|---|---|---|---|
| 409 (Conflict) | 40228 | Failed to create CallAgent, an instance of CallAgent associated with this identity already exists. | ExpectedError |
| 408 (Request Timeout) | 40104 | Failed to create CallAgent, timeout during initialization of the calling user stack. | UnexpectedClientError |
| 500 (Internal Server Error) | 40216 | Failed to create CallAgent. | UnexpectedClientError |
| 401 (Unauthorized) | 44110 | Failed to get AccessToken | UnexpectedClientError |
| 408 (Request Timeout) | 40114 | Failed to connect to Azure Communication Services infrastructure, timeout during initialization. | UnexpectedClientError |
| 403 (Forbidden) | 40229 | CallAgent must be created only with ACS token | ExpectedError |
| 408 (Request Timeout) | 40114 | Failed to connect to Azure Communication Services infrastructure, timeout during initialization. | UnexpectedClientError |
| 403 (Forbidden) | 40229 | CallAgent must be created only with ACS token | ExpectedError |
| 412 (Precondition Failed) | 40115 | Failed to create CallAgent, unable to initialize connection to Azure Communication Services infrastructure. | UnexpectedClientError |
| 403 (Forbidden) | 40231 | TeamsCallAgent must be created only with Teams token | ExpectedError |
| 401 (Unauthorized) | 44114 | Wrong AccessToken scope format. Scope is expected to be a string that contains voip |
ExpectedError |
| 400 (Bad Request) | 44214 | Teams users can't set display name. | ExpectedError |
| 500 (Internal Server Error) | 40102 | Failed to create CallAgent, failure during initialization of the calling base stack. | UnexpectedClientError |
How to mitigate or resolve
The application should catch errors thrown by createCallAgent API and display a warning message.
Depending on the reason for the error, the application may need to retry the operation or fix the error before proceeding.
In general, if the error category is UnexpectedClientError, it's still possible to create a call agent successfully after a retry.
However, if the error category is ExpectedError, there may be errors in the precondition or the data passed in the parameter that need to be fixed on application's side before a call agent can be created.