Configure Vonage Programmable SIP trunking with inbound call webhooks

Steps

1. Log in to the Vonage API Dashboard and create a Voice application; in the application settings, set the Answer URL (the HTTP endpoint Vonage calls when an inbound call arrives) and the Event URL (for call lifecycle events) using HTTPS.
2. Navigate to SIP > SIP Dashboard and link your Voice application to a Vonage SIP domain (e.g., yoursubdomain.sip.vonage.com); your PBX or softphone registers to or routes calls through this domain.
3. For inbound calls, Vonage fetches your Answer URL and expects an NCCO (Nexmo Call Control Object) JSON array in response; return an NCCO with actions such as 'talk', 'connect', or 'record' to control the call flow.
4. For outbound calls via SIP, use the Vonage Voice API to create a call (POST to /v1/calls) with a to array specifying type: 'sip' and the target SIP URI, and a from object with your Vonage number.
5. Configure your PBX to authenticate with the Vonage SIP domain using the SIP credentials generated in the SIP Dashboard, or use IP-based authentication if your PBX has a fixed public IP.
6. Test connectivity by dialing the Vonage SIP domain from a registered SIP client and verifying that your Answer URL receives a POST request; inspect the event log in the Vonage Dashboard for detailed call traces.