Hello Vapi Support Team, I’ve been trying to connect my Asterisk SIP extension 1101 to Vapi.ai for the past two weeks, but it’s still not connecting. I’ve checked my Asterisk server logs, and there’s no registration or connection request being received from Vapi’s side. The extension appears as “Not Connected” in both the Asterisk CLI and my dashboard. It seems like Vapi isn’t sending the SIP registration request to my server. When I attempted a test call, I received the response “Customer Busy” even though the server wasn’t connected. Details: Call ID: 0199e4d8-5624-700a-b2ce-8ae147fc3e3a Timestamp: 2025-10-24 03:40 PM (GMT+6) Expected Response: SIP registration or call setup request Received Response: Customer Busy Please check this issue and connect me with a human live support agent to resolve it. Thank you, Farhan Al Masud https://cdn.discordapp.com/attachments/1431038180597170357/1431038180869804115/Screenshot_2025-10-24_at_3.51.01_AM.png?ex=68fbf5a9&is=68faa429&hm=754d5645615f3042d2f957f9a5d9f113bc1aaaf64f5b9b683cb1ef43a83e16a5&

Action Step: Please ensure your Asterisk server is configured to accept SIP connections from Vapi by allowlisting these IPs:

44.229.228.186/32
44.238.177.138/32

After allowlisting, create a SIP trunk credential in Vapi using your provider details. Example API call:

bash
curl -X POST "https://api.vapi.ai/credential" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_VAPI_PRIVATE_KEY" \
  -d '{
    "provider": "byo-sip-trunk",
    "name": "Asterisk Trunk",
    "gateways": [{ "ip": "YOUR_ASTERISK_SERVER_IP", "inboundEnabled": true }]
  }'

This should enable Vapi to connect to your Asterisk extension. For full steps, see the [SIP trunking guide](https://docs.vapi.ai/advanced/sip/sip-trunk). Source: - [SIP Trunking Guide](https://docs.vapi.ai/advanced/sip/sip-trunk)

@Flemsoft Based on your screen capture and report - are you trying to connect Vicidial ?

Hi Flemsoft, To get started with integrating your Plivo SIP trunk to Vapi for inbound and outbound calls, you should follow the configurations outlined in the [Plivo SIP Integration Guide](https://docs.vapi.ai/advanced/sip/plivo). Here's a quick overview of the main steps: 1. Plivo Configuration: - Create a new IP Group in Plivo's Zentrunk (SIP) section with the IP addresses

44.229.228.186/32

and

44.238.177.138/32

. - Set up an Outbound Trunk linked to this IP Group and take note of the Termination SIP Domain. - Purchase a phone number and configure your Inbound Trunk with the URI

sip.vapi.ai;transport=udp

. 2. Vapi Configuration: - Obtain your Vapi API key via the Vapi dashboard. - Use API calls to create SIP trunk credentials, associate your Plivo number, and configure inbound/outbound settings with the Termination SIP Domain. Remember to ensure only supported codecs (G.711 µ‑law and A‑law) are enabled on your trunk. Also, note that SIP REFER is not supported by Plivo for call transfers. You might find further helpful details in the [SIP Trunking Guide](https://docs.vapi.ai/advanced/sip/sip-trunk), which provides additional context for integrating any SIP provider with Vapi. If you have specific steps you need more clarity on or encounter any errors, please let me know.