I have created a tenant issue reporting system using VAPI and Make.com. Part of the system makes a transient outbound call triggerred from within make.com. The call asks a contractor if they can handle an issue (previously reported by the tenant), if "No" then the transient call makes a function call to a webhook in a separate make.com scenario which then enables the selection of the next contractor (from a google sheet). All this works well EXCEPT when the transient call encounters a voicemail or silence (no answer) - the transient call "times out" after a number of seconds and does NOT trigger the function tool (to alert the make.com scenario) so it can select the next contractor. I am seeking help on how I can ensure the transient call does not timeout before triggering the function tool. Any advice would be appreciated.

Hi, I can help make sure the transient call triggers your webhook even if it hits voicemail or silence. We can adjust the call to handle timeouts and no-answer events so the Make scenario always runs. Are you currently using VAPI’s on.no_answer or on.hangup event hooks, or only the function tool? This will help determine the best setup to prevent missed triggers. @Lee

Hi Lee, To troubleshoot why calls drop immediately after initiating a transfer, follow these steps: 1. Verify Forwarding Initiation: - Check if Vapi initiated the call forwarding using the API:

bash
     curl -X GET "https://api.vapi.ai/call/{call_id}" \
     -H "Authorization: Bearer YOUR_API_KEY" \
     -H "Content-Type: application/json"

- The

endedReason

should be

"assistant-forwarded-call"

. If different, review your assistant configuration to ensure forwarding is set up correctly. 2. Review Assistant Configuration: - Ensure the

serverMessages

configuration does not include

"phone-call-control"

. - Set

phoneCallProviderBypassEnabled

to

false

unless implementing custom control. 3. Confirm Transfer Feasibility: - Confirm your transfer scenario is supported. For example, web-to-phone transfers are unsupported. 4. Telephony Provider Checks: - Use the

phoneCallProviderId

to check your telephony provider's logs for any transfer-related issues. Each provider has a dedicated dashboard for troubleshooting: - [Twilio](https://console.twilio.com/us1/monitor/logs/calls) - [Vonage](https://dashboard.nexmo.com/) - [Telnyx](https://portal.telnyx.com/) 5. SIP Analysis (if applicable): - Download and analyze the SIP packet capture with Wireshark. Look for the "REFER" packet to verify if the transfer request was sent. For further guidance, you can refer to the [Debug call forwarding drops guide](https://docs.vapi.ai/phone-calling/transfer-calls/debug-forwarding-drops). If these steps do not resolve the issue, examining telephony provider error logs and configurations may provide additional insights.