We have been using Vapi for some time now and today while deleting unused SIP credentials from the web interface, and possibly due to a web portal bug, our live credential got deleted. We are trying to recreate this but it is giving errors: { "provider": "byo-sip-trunk", "name":"VCAGENT1002", "gateways": [ { "ip": " cc04727.atmoviacc.viacloud.com ", "port": 5061, "outboundEnabled": true, "outboundProtocol": "tls/srtp" } ], "outboundAuthenticationPlan": { "authUsername": "", "authPassword": "Jd****ZH6F", "sipRegisterPlan": { "domain": "cc0****ud.com", "username": "1002", "realm": "" } }, "outboundLeadingPlusEnabled": false } The error is: { "message": "Couldn't validate SIP trunk credential. SIP gateway creation failed.", "error": "Bad Request", "statusCode": 400 } We have verified the credentials are ok, and when adding with IP instead of the FQDN in gateway 0, the credential is being added (and we are then updating the gateway 0 with api from ip to FQDN which is being accepted and updated in the credential) but the calls are not working, it seems the sip user is not being registered at all from Vapi side.

Hi Santosh G., I see you're looking for information related to setting up or managing SIP trunk credentials. Here's an overview of what you might need: 1. **Creating SIP Trunk Credentials**: Ensure you have the necessary properties such as the provider, gateways (with IP, port, netmask), and any outbound protocols configured correctly. You can refer to [this documentation](https://docs.vapi.ai/api-reference/assistants/create) for detailed steps. 2. **Handling SIP Call Errors**: Specific error codes have been introduced for better identification of failures like

call.in-progress.error-sip-inbound-call-failed-to-connect

and others. It might be beneficial to update your error handling to use these specific codes, as outlined in the [changelog](https://docs.vapi.ai/changelog/2025/5/31). 3. **Troubleshooting SIP Trunk Issues**: Check that all mandatory fields like

provider

,

ip

, and protocols are correctly set as per your region and service requirements. If you need further details or have specific errors to discuss, please let me know.