The ability to capture Touch Tone input such as a call transfer password and then be able to redirect the call to an external line using another captured input such as the phone number enter.
e.g.
Press 1 to leave a message to Eric
Press 2 to leave a message to Louise
Press 3 to transfer your call.
If 3 is pressed you are prompted with
Please enter your system password.
If the password is entered correctly you are prompted with.
Please enter the phone number you want to be transfered to.
The system would then call transfer you through you PSTN or SIP to the number you dialed.
You could call your system from your cell phone or a friends house and then call free long distance from your 3CX PBX.
