VAPI•4mo ago

Issue with TelTel

Hello! I’m developing an AI caller app with Vapi (Electron desktop).
Connectivity works: I can list assistants, create a BYO SIP trunk, and import my DID.

Issue:
• When I start a demo call (POST /call/phone), the API returns a callId and the call appears in Vapi logs, but it is immediately rejected with different statuses (no ringing/connection).

My setup:
• Provider: <TelTel or other>.
• SIP trunk credentialId: <CRED_ID>.
• PhoneNumberId (from Vapi): <PN_ID>.
• AssistantId: <ASSISTANT_ID>.
• SIP gateway host: <HOST>, resolved IP: <IP>.
• Auth: username=<USER> / password=** (registration <on/off>, realm/domain: <VALUE>).
• Dial format: tried E.164 with “+” and without.
• From: <MY_DID>, To: <DEST_NUMBER_E164>.

Recent failing calls:
• callId <6265fcfd-f4f2-4e4b-9847-787f694376ca>
• callId <894b88c8-e9a2-44e9-acf9-94b8af171dda

Happy to provide full request/response snippets if needed. Thanks!

KyleAPP•9/11/25, 2:49 PM

Hi 4DoorsMoreWhores,

When your demo call is immediately rejected with different statuses and no ringing or connection occurs, several factors might be at play. Here’s a troubleshooting checklist based on common issues associated with calls being rejected:

Check Call Ended Reason: Verify the endedReasonendedReason field in your call logs to understand why the call did not progress. You can find all possible reasons here.
SIP Credential Configuration: Ensure that your SIP trunk credentials are correctly set up. Check that credentialIdcredentialId is properly associated with the right configuration for your service provider.
Connection Status: Double-check that your network and SIP service provider configurations allow call traffic. Investigate telephony provider logs for any rejected connection attempts.
Provider Settings: Review the settings with your SIP provider to ensure their system isn’t blocking or rejecting the calls. Provider-specific settings sometimes need adjustments for compatibility with Vapi.
Server Messages Configuration: Make sure your assistant’s serverMessages configuration doesn't include phone-call-controlphone-call-control unless you're managing call logic outside of Vapi.
Call Control Settings: Check if phoneCallProviderBypassEnabledphoneCallProviderBypassEnabled is set correctly. It should typically be falsefalse unless custom call logic is implemented through your provider.
Check SIP REFER Packets: If you're using SIP and the call is not transferred correctly, analyze the SIP packets as detailed in our debug call forwarding guide.

By understanding these aspects, you can better isolate where the call process is breaking down. If the issue persists after these checks, you might need to verify your setup configurations with both Vapi and your SIP provider.

Issue with TelTel

Similar Threads

Similar Threads

Similar Threads