The Consultative Transfer is supported if:
The transfer-system full-consult command (default) is set in telephony-service configuration mode.
The transfer-mode consult command (default) is set for the transferor's directory number (ephone-dn).
An idle line or channel is available for seizing, digit collection, and dialing.
Cisco Unified CME 4.3 and later versions enable these transfer enhancements by default.