Intermittent SIP failures with the Realtime API

Hi everyone,

We have been experiencing intermittent instability with our SIP integration using the Realtime API, with multiple occurrences of normal temporary failure errors.

The issue is not consistent: sometimes the integration works as expected, and other times it fails with the same error, even when using the same project, the same SIP configuration, and the same endpoint.

So far, we have not been able to identify the root cause on our side. We have already opened a support ticket with OpenAI, but we have not yet received feedback that helps us move forward with the investigation.

Is anyone else seeing similar intermittent issues with SIP and the Realtime API?

In particular, I would appreciate any insight on:

• Whether you are also seeing recurring normal temporary failure errors;

• Whether the failures are intermittent for the same project, configuration, or endpoint;

• Whether the issue appears in specific scenarios

• Which logs, metrics, or SIP traces helped you narrow down the root cause;

• Any known mitigation, configuration change, or best practice that improved stability.

Any suggestions or shared experiences would be very helpful.

Thanks in advance.