Problem: When our VAPI assistant makes outbound calls to Brazilian phone numbers, approximately 1 in 4-5 calls result in: - Customer hears complete silence (no audio from assistant) - Customer speech is not transcribed or recorded in call logs - Call logs show the first message audio was generated, but customer never heard it - No customer audio appears in the transcript

I’ve seen this happen before with VAPI calls to Brazil — it’s often linked to how local carriers handle RTP or SIP media routing. I can help pinpoint whether it’s a codec, carrier, or session setup issue and apply fixes to stabilize audio flow. Could you share which provider you’re using for these outbound calls — Twilio, Telnyx, or another? @moon

We're using Twilio and just to clarify - this issue occurs when the call is made from a Brazilian number to Korean number. @Vercel

Since this happens from a Brazilian Twilio number to a Korean number, it’s likely due to international media routing or SIP/codec negotiation issues. I can review the call flow and logs to pinpoint the cause and fix the audio and transcript gaps. Could you share recent call SIDs for troubleshooting? @mori

Thank you! Recent call SID: CAa388cb7855a6e2ce25a2a131422b4934

Thanks @mori for the clarification. @Vercel Just checking — is this information sufficient for you to move forward? If you need additional call SIDs or logs, I can share them right away.

Hi moon, If you need assistance regarding call ended reason codes or troubleshooting outbound calls, the following information might be helpful: 1. **Call Ended Reasons**: You can explore various reasons for calls ending with specific codes in the [Call Ended Reasons documentation](https://docs.vapi.ai/calls/call-ended-reason). 2. **Debug Call Forwarding**: If you're dealing with call forwarding issues, consult the [Debug Call Forwarding Drops guide](https://docs.vapi.ai/phone-calling/transfer-calls/debug-forwarding-drops). It contains steps to troubleshoot forwarding problems effectively. 3. **Outbound Calling**: For setting up and managing outbound calls, make sure all configurations are correctly set per the [Outbound Calling](https://docs.vapi.ai/calls/outbound-calling) guide. Ensure your assistant, phone number, and customer details are properly entered. Let me know if there's anything else you need help with.

Hi @moon please watch out for @User . He says he knows the answer to your problem and he can help. But he will ask for money upfront. I made the mistake of doing so and never heard back from him. I already reported him in the # report-scam channel. But I wanted you to be aware of him. Cheers!

Ah I see. Thank you for your kindness@Charlie