I would like to share an update regarding our SIP trunk integration. We have successfully connected our local provider’s SIP trunk and phone numbers to Vapi for inbound calls. However, we have been facing ongoing challenges with configuring the outbound routing. We have been actively working on this for more than three months, but unfortunately, we have reached a point where we are unable to move forward without direct technical guidance. At this stage, I would highly appreciate dedicated support from your team to help us finalize this setup. If possible, I would like to request a one-on-one meeting or live session with a technical specialist so we can resolve this efficiently. This integration is critical for our project, and completing it with your support would make a significant difference. If a live session is not feasible, I would be grateful for an alternative communication channel (such as a direct support thread or technical contact) that would allow for faster and more effective collaboration.

@jimmy What exactly are you experiencing? I'm not a VAPI employee, but maybe I can point you in the right direction.

Hi jimmy, Thanks — we can help. Please reply with the following so we can either resolve remotely or schedule a live session: 1. A recent failing outbound Call ID (one example). 2. Timestamp (UTC) of that call. 3. Your SIP credential configuration in Vapi (credential id and the gateways block you used). 4. Your provider’s expected outbound/termination SIP host and any auth method they require (IP-based or username/password). 5. The exact SIP/HTTP error you see in Vapi or your provider (401, 403, 4xx/5xx, SIP response text like "Customer Busy", or Vapi endedReason). 6. Whether outbound calls from the same SIP trunk succeed when made directly from your softphone/PBX (you said yes earlier — confirm). 7. Preferred times (with timezone) for a 30–60 minute live troubleshooting session and a contact method (Zoom/Google Meet). While you gather that, please confirm you have allowlisted Vapi SIP IPs 44.229.228.186 and 44.238.177.138 on your provider/firewall per our SIP Trunking guide: https://docs.vapi.ai/advanced/sip/sip-trunk Once you send the items above I’ll triage logs and either provide targeted config changes or arrange a technical session.

1. 019b019f-a7b7-7665-b012-ea3fcab68aeb

@jimmy Do you have SIP trace from your gateway side of the calls?

Remove inbound for both trunks and it should work