Hi Tried importing a Telnyx phone number through the native Vapi "Create phone number". It works, but the audio quality is so bad, that the agent can't understand what I'm saying. This is a known issue (https://discord.com/channels/1211482211119796234/1366869224798031953) and the only fix seems to be setting up a SIP Trunk instead. However, setting up a SIP Trunk with inbound enabled also doesn't work (https://discord.com/channels/1211482211119796234/1402670221826723973/1402670221826723973) What's the best way to make this work?

To improve audio quality and enable inbound calls, set up a Telnyx SIP trunk in Vapi using the API. Here’s a concrete example to add your Telnyx SIP credentials:

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": "Telnyx Trunk",
    "gateways": [{ "ip": "sip.telnyx.com" }],
    "outboundAuthenticationPlan": {
      "authUsername": "YOUR_SIP_USERNAME",
      "authPassword": "YOUR_SIP_PASSWORD",
      "sipRegisterPlan": { "realm": "sip.telnyx.com" }
    }
  }'

Replace the placeholders with your actual credentials. This is the recommended way to integrate Telnyx for better call quality and inbound support ([Vapi Telnyx SIP integration guide](https://docs.vapi.ai/advanced/sip/telnyx)). Source: - [Vapi Telnyx SIP integration guide](https://docs.vapi.ai/advanced/sip/telnyx)

This doesn't work. You get a "couldn't validate SIP trunk credential". This is not because of the outbound credentials - if I add the "inboundEnabled=false" parameter, the SIP is created without issues. This is the error message I get: Invoke-RestMethod : {"message":"Couldn't validate SIP trunk credential. SIP gateway creation failed.","error":"Bad Requ est","statusCode":400} At line:1 char:1 + Invoke-RestMethod -Uri "https://api.vapi.ai/credential" ` + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (System.Net.HttpWebRequest:HttpWebRequest) [Invoke-RestMethod], WebExc eption + FullyQualifiedErrorId : WebCmdletWebResponseException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand

Thank you for providing this information. We’ll be looking into it further to better understand the situation and determine the next steps. Our team will update you as soon as we have more details, and we truly appreciate your patience and cooperation in the meantime.

Any news?

We apologize for the delay in responses lately. We are in process of making some changes to our workflow in how we handle support requests. The good news is that we are starting to get back on track of having a 48 hour response time and we would like to start cleaning up anything old. With that being said, just wanted to check in with you to see if you have made any progress or changes to your project since support has last reached out. /