Dear Vapi Support Team, I would like some assistance on configuring my inbound calls using my own SIP trunk (BYOC) with Vapi.ai to leverage my existing PBX (Yaxxa in this instance in NZ). I have tried following the steps provided in the documentation and have also connected with Yaxxa to no avail. Would love to connect with one of the engineers to know what would be the issue when connecting my own SIP Trunk.

Hi there, Thank you for your message. Our team is currently out of the office. We operate Monday through Friday, from 9:00 AM to 8:00 PM Pacific Standard Time (PST). We’ll get back to you as soon as possible during our normal business hours. If your message is urgent, please mark it accordingly or include “URGENT” in the subject line, and we’ll do our best to respond promptly. Warm regards, Vapi Customer Support Team

I can assist in configuring your inbound calls with your BYOC SIP trunk on Vapi.ai using your Yaxxa PBX. To start, it would help to know if you’re seeing SIP registration errors or call routing issues. Once identified, we can systematically check trunk settings, authentication, and PBX routing to isolate the problem. This approach ensures a smooth connection and minimizes trial-and-error. Could you share if you’re seeing any SIP registration errors or call routing issues? @Ivan

Hi, here's my response to your query and hopefully it answers it https://cdn.discordapp.com/attachments/1447290378024652881/1447716429452284135/f56e5bfe-f155-4235-869e-93bac3ac268a.png?ex=6938a27e&is=693750fe&hm=6e0222598f344c6bbcc3f9ca95e552c479e7ea68485dfeee6884950d9c7d6f4e&

Thanks for sharing that update it actually helps narrow things down. From here, the right approach is to trace where the IP-to-tenant conflict is happening on the carrier side, then align your Vapi BYOC settings and PBX routing so the trunk is mapped cleanly to a single account. The fastest way is to review your SIP auth, trunk registration path, and Vapi routing rules together end-to-end. If you’d like, I can jump in directly and handle the full configuration so you don’t keep running into these carrier-level errors, it’ll save you time and get everything stable quickly. @Ivan

Hi, to configure the SIP Trunk, please follow the documentation for whitelisting the IP addresses: Then use this template as a guide to configuring both inbound and outbound gateways. The inbound gateway will need a static IP address and the outbound gateway will use the resolved domain name using UDP protocol:

{
  "provider": "byo-sip-trunk",
  "name": "My SIP Trunk",
  "gateways": [
    {
      "ip": "sip.provider.com",
      "port": 5060,
      "outboundEnabled": true,
      "inboundEnabled": false,
      "outboundProtocol": "udp"
    },
    {
      "ip": "203.0.113.10",
      "port": 5060,
      "outboundEnabled": false,
      "inboundEnabled": true
    }
  ]
}

Once you have configured the SIP trunk, you will receive a value for credentialId. Save that and use it for the next step of assigning the SIP trunk to a phone number, as that is a required value for setting up the phone number. If you encounter any issues with the setup, please feel free to reach out.

Hi @Tremix sorry I haven't been able to reply for a few days - sure! can you help me with this? it would so much save me a lot of time. Are you also available for a call? Let me know if youre available 🙂

Absolutely, I can help you with this and save you time. Let’s discuss the details privately so we can schedule a call at a time that works best for you and go through the setup step by step. This will ensure we address the carrier and PBX configuration efficiently and avoid repeated errors. @Ivan

If you need additional assistance setting up the trunk, please let us know