Is call transfer supported?
Yes. Call transfer functionality is fully supported across all environments. Whether you are using a simple Voice XML script or dynamically redirecting calls via the REST API in response to AI Voice agent sentiment analysis.
Supported Routing Methods
1. The `<Dial>` XML Tag
The primary method for bridging a live caller to another party is utilizing the standard <Dial> XML noun within your BXML response. This seamlessly acts as a warm or cold transfer, taking the initial call endpoint and natively connecting it to a new SIP URI or E.164 phone number.
2. REST API Live Transfer
If an active live call is already in progress (e.g., executing a WebRTC stream to Retell AI) and you need to perform an out-of-band network transfer dynamically (such as transferring a frustrated user to a human agent immediately), you can use the REST API to actively `Update` the Call state and point it to a completely new destination XML layout using the /transfer-call endpoint.
3. SIP REFER (Blind/Attended SIP Transfer)
If you are natively connecting via SIP hardware (like an IP Desk Phone or PBX) rather than APIs, Vobiz supports RFC 3515 standard `SIP REFER` messages. This allows your authenticated SIP endpoints to trigger blind or attended transfers cleanly at the network layer without requiring additional code overhead.
Supported on verified SIP Trunks only.