Hi, I’m using Vapi with n8n and a Sipgate.de trunk. Inbound works perfectly, but with outbound (even directly from Vapi) I always get the error call.in-progress.error-providerfault-outbound-sip-403-forbidden. The settings are correct (since inbound works), Sipgate says the IPs are not blocked. I’ve also recreated the BYO SIP credential, but outbound still doesn’t work and I keep getting the same error. Thanks Call id: 9cf4277d-a06d-4e02-a68b-a06e20e40d58 Timestamp: 16th Sep, around 22:30 CET

Suggestion: Double-check that your outbound SIP trunk credential in Vapi includes the correct authentication details (username and password) for Sipgate.de, as outbound 403 errors often result from missing or incorrect credentials. Here’s an example of how your credential setup should look:

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": "Sipgate Trunk",
    "gateways": [{ "ip": "sipgate.de" }],
    "outboundAuthenticationPlan": {
      "authUsername": "YOUR_SIPGATE_USERNAME",
      "authPassword": "YOUR_SIPGATE_PASSWORD"
    }
  }'

Ensure the username/password match your Sipgate outbound credentials exactly. [Reference: Vapi SIP Trunk Setup](https://docs.vapi.ai/advanced/sip/sip-trunk#setup-process) Source: - [SIP Trunking | Vapi Documentation](https://docs.vapi.ai/advanced/sip/sip-trunk)

here are the key points for troubleshooting your [Sipgate.de](http://Sipgate.de) outbound calling issue: 1. For outbound calls, verify your SIP trunk configuration: - Ensure Vapi's static IPs are whitelisted: - 44.229.228.186 - 44.238.177.138 - These need to be whitelisted for the entire IP range [1](https://docs.vapi.ai/advanced/sip/twilio) 2. In your Vapi BYO SIP trunk credential configuration, check: - The

outboundLeadingPlusEnabled

parameter is set correctly - The gateway IP/hostname is properly configured - The

inboundEnabled

parameter matches your needs 3. The "403 Forbidden" error typically indicates an authentication or authorization issue. Double-check: - Your SIP trunk credentials - IP authentication settings in Sipgate - That your Sipgate account has outbound calling permissions enabled You may want to recreate your SIP trunk credential with this format:

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

Let us know if further assistance is needed.