SIP Trunk Registration Failures During Load Testing with High Concurrent Volumes

Is it possible to configure Genesys Cloud to handle 500 concurrent SIP registrations without triggering temporary bans on our trunk credentials? We are running a load test using JMeter to simulate peak call volumes for our new deployment. The goal is to verify call capacity planning before going live. However, the SIP trunk registration fails after a specific threshold is reached. The error log shows 403 Forbidden with the message Too many registration attempts. This happens even though we are using valid credentials and the rate limits in the API docs seem higher.

Here is how we reproduce the issue:

  1. Create a SIP trunk connection in Genesys Cloud with standard settings.
  2. Configure JMeter to send REGISTER requests to the Genesys SIP endpoint.
  3. Set the thread group to 500 users with a ramp-up period of 10 seconds.
  4. Run the test and monitor the response codes.

We expect all registrations to succeed, but about 200 requests fail with the 403 error. Is there a specific configuration for SIP trunk concurrency or a rate limit we are missing? We are using the latest Genesys Cloud API versions.