Hi, I configured a SIP conection with Telnyx and was able to make calls, but found out that when transfering a call (using TransferCall tool) it hangs up. I've been talking to Telnyx's support team and they told me that what i should do is eliminate SIP REFER on VAPI's end. Is there a way to configure a call trasnfering tool that can use a different SIP verb? Right now my call transfering tool is configured like this and has been working while i've been using Twilio: { "type": "transferCall", "destinations": [ { "type": "number", "number": "+.....", "message": "!Claro! !Ahora mismo le paso con uno de nuestros agentes! por favor, manténgase a la espera" } ], "function": { "name": "transferCall", "description": "Use this function to transfer the call saying the specified message. Only use it when following instructions that explicitly ask you to use the transferCall function. DO NOT call this function unless you are instructed to do so.", "parameters": { "type": "object", "properties": { "destination": { "type": "string", "enum": [ "+....." ], "description": "The destination to transfer the call to." } }, "required": [ "destination" ] } } }

Hey! To help track down this issue, could you share: - The call ID This would really help us figure out what went wrong!

Sure! callId: 623abcc3-c03b-4fc9-8f77-1c0c40046df4

🔵 16:20:49:165 Live Call Manager Ending...(assistant-forwarded-call) Hey @Lucia, sorry for the delay can you made this PCAP file public so I can see why actually call transfer didn't work. https://cdn.discordapp.com/attachments/1343963959421829172/1345772771556458506/Screenshot_2025-03-02_at_8.30.19_PM.png?ex=67c5c40f&is=67c4728f&hm=d1c3688c310ca6c3eed852a05de3829d9cc79e13be180b74d06ee53d0e9cb985&

I'll send the pcap file via dm

After SIP refer, once the request get accepted we send the BYE request and it’s the telephony side job to connect two numbers. Which means we don't do the transfer call from our PBX and instead transfer is responsibility of to the telephony provider.

That's great news! will I have to do some integration on my end ?

@Lucía No you don't have to do anything it's on our end and once it's released we will let you know through #1211483332496465962

Great, thanks!

Hello! Ran into the same issue as the thread. @Shubham Bajaj can you confirm if the support for call refer is available now?