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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.

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Supported Routing Methods

  • The <Dial> XML tag - The primary method for bridging a live caller to another party. Use the standard <Dial> noun within your BXML response to warm- or cold-transfer the caller to a new SIP URI or E.164 phone number.
  • REST API live transfer - If a call is already in progress (e.g., streaming to Retell AI) and you need to redirect dynamically (such as escalating a frustrated user to a human agent), Update the call state via the /transfer-call endpoint to point it at a new XML destination.
  • SIP REFER (blind/attended SIP transfer) - If you connect natively via SIP hardware (IP desk phone or PBX) rather than APIs, Vobiz supports RFC 3515 SIP REFER messages so your authenticated SIP endpoints can trigger blind or attended transfers at the network layer.
SIP REFER is supported on verified SIP Trunks only.