Hi folks, hope you are all well. I been digging through prior threads and can't seem to find one that covers my current issue. We have successfully integrated Twilio with VAPI, and are able to trigger the callTransfer tool and are forwarded to a RingCentral number. We are now trying to see if we can call forward to an extension in RingCentral. The extension could be to a user or queue. Has anyone successfully accomplished this and what was needed.

You can use the transferCall tool in VAPI to send calls to specific numbers, but direct forwarding to RingCentral extensions requires using Twilio’s Elastic SIP Trunking with SIP REFER messages to initiate the transfer.

Thanks @Kings_big💫 I appreciate the reply - We have successfully set up transferring to RingCentral via Twilio using VAPI, but we are having difficulty configuring it so that it transfers to an extension. From current research it seems we need to set up the

refer-to

so that it looks like `sip:@`; but not sure if that is correct. The issue is not forwarding to a number but to a number's extension.

@bernardo Sorry to say, I don't believe that is supported via VAPI's transfer capability. VAPI transfer is performed via

SIP REFER

for warm transfer, and a simple dialing outbound for cold transfers (if I remember correctly). In both cases, the

SIP REFER URI

that is provided to Twilio includes only a phone number, and if specifying a remote domain, the transfer will fail, as Twilio will not

REFER

to a domain outside Twilio (security and toll-fraud restrictions). You can do something like that using Cloudonix and our

Switch Voice Application

API call. DM me and I'll walk you through the process.

@Nir Simionovich (CEO@Cloudonix) thanks for helping @bernardo

Thanks @Nir Simionovich (CEO@Cloudonix) I have a working solution for the moment (using secondary twilio number and webhook endpoint). Still just working through what can be done solely with Twilio and VAPI. @Shubham Bajaj ~I do have a follow up question, regarding the ability to forward to a number before an assistant responds. Just started looking to see if this is a possibility.~ nvm - figured how to handle this; using the control url.

Hey bernardo, let me know if you require any further help related to this.