@Mattia Good morning, Mattia! Yes, it is indeed possible to integrate an outgoing call assistant with different providers, including Messagenet or a SIP trunk you've created with Colt as PSTN. While our documentation may specifically mention Twilio or Vonage, our API is designed to be flexible and can work with other providers that support SIP or similar protocols. To integrate with a provider not explicitly listed in our documentation, you would typically need to ensure that the provider supports the necessary voice and call control APIs that are compatible with our system. The provider would need to be able to handle SIP requests and responses, manage call setup and teardown, and support the transmission of audio streams. Unfortunately, we do not have a specific guide for integrating each potential provider, as the details can vary significantly between them. However, you can generally follow these steps: 1. Ensure that your provider supports the necessary protocols and APIs for voice communication. 2. Configure your provider's settings to work with our API endpoints, such as /call/phone. 3. Set up authentication and any necessary credentials to allow our API to interact with your provider. 4. Test the integration thoroughly to ensure that calls are routed correctly and that voice quality is acceptable. If you need more detailed assistance or have specific questions about integrating with a provider like Messagenet or Colt, please reach out to support for more info on this. We're here to help you through the process! Best regards, VAPI Support Team

@User can you help me?

what is the gateway ip when using twilio? I have tried several ones but it does not work for me.