Can anyone clarify why my BYOC trunk fails registration with a 407 Proxy Authentication Required error? In Zendesk, we just pushed credentials via API. Here, I see the trunk status as ‘Failed’ immediately after toggling it on. I’ve verified the username and secret match the partner portal exactly. Is there a specific header Genesys expects that Zendesk didn’t require?
If you check the docs, they mention that BYOC trunk registration in Genesys Cloud relies on standard SIP 401/407 challenge-response mechanisms, not just static credential matching. The 407 error usually indicates the proxy is rejecting the initial REGISTER request because the Proxy-Authorization header is missing or malformed. In Zendesk Voice, the platform often handled the handshake abstraction. Here, you need to ensure your SIP provider supports digest authentication with the realm specified in the 407 challenge.
From a load testing perspective, I have seen this fail immediately when the trunk is toggled on without allowing the SIP stack to stabilize. The initial burst of registration attempts can look like a flood attack to the upstream proxy if not throttled. Try adding a small delay before enabling the trunk. If the issue persists, capture the SIP trace. Look for the WWW-Authenticate or Proxy-Authenticate header in the 407 response. It will contain a realm and a nonce. Your SIP endpoint must calculate the response digest using the username, password, realm, nonce, method (REGISTER), and URI. If your provider sends a basic auth header instead of digest, it will fail. Also, check if there is a firewall rule blocking SIP OPTIONS or REGISTER packets on port 5060/5061. I use JMeter to simulate SIP traffic, but for registration, the native SIP stack is more reliable. Ensure the partner portal credentials are not expired. Sometimes the secret key rotation causes this. Verify the timestamp in the SIP message matches the server time. A skew of more than 30 seconds can cause digest failures. Check the system logs for SIP_REGISTRATION_FAILED events. They provide the exact reason code. If the code is AUTH_FAIL, it is definitely a credential or digest calculation issue. If it is TIMEOUT, it is a network path issue. Start with the digest calculation. Use a SIP debugging tool to verify the header construction. This usually resolves the 407 error quickly.