h1. Blind transfer

*Blind transfer* - uncontrolled call transfer to a different number.

!transfer.gif!

This works as follows:

Subscriber A dials subscriber B.
Each of subscribers can dial special DTMF sequence, defined in option *attended transfer* of menu [[PBX settings]]->DTMF features.
By default it's *1.

Let's assume, attended transfer is initiated by subscriber B.
After this he will hear voice prompt - "pbx-transfer" by default.
You can define another voice prompt by loading audio file using instruction from section [[Audio prompt upload]] and replacing file "pbx-transfer".

Next subscriber B will hear dial tone. 
Subscriber A will be put on hold and will hear music on hold. 
Now subscriber B can dial subscriber C, to which he wishes to transfer the call.

When dialing, system takes into account *transfer digit timeout (sec)* option of menu [[PBX settings]]->Call transfer.
In case if DTMF digit is not entered during that time, system assumes that full number has been entered.
A set of digits entered before timeout has elapsed is accounted as a full number to call.

In case if no number is dialed during *transfer digit timeout (sec)*, subscriber will hear voice prompt "pbx-invalid", and will be returned back to original subscriber.
You can define another voice prompt by loading audio file using instruction from [[Audio prompt upload]] and replacing original file "pbx-invalid".
This behavior will be in case if you dial extension for which there is no [[Pattern extension]] defined.

In case if number is entered correctly and it matches existing [[Pattern extension]], then system hangs up subscriber B and invokes outgoing call to subscriber C.
Subscriber A hears ring-back from outgoing call.

When subscriber C picks up, he is connected with subscriber A.

An example of configuring is located at section [[Configuring call transfer]].

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