In most of the useful IVR Software deployed in real world, has a feature where the incoming call to IVR has to be connected to a human agent (in a call center) or to a person with whom the call can talk. In telecom jargon, this is known as “call transfer” and this is a standard feature for any CTI board.
While this simple job of “Call Transfer” seems quite simple, but its implementation is totally different from analog CTI boards ( like Dialogic D/4PCI) than digital CTI boards ( like Dialogic D300 1 port PRI). While many people use “Call Patching” for call transfer while using a digital CTI board, but it is also possible to transfer a call by sending “Call Transfer” command to switch/PBX. In Analog Boards, easiest way to transfer call is simply following the traditional way of call transfer, hook flash, dial the desired extension, put telephone receiver on hook again.
And the good news is, Dialogic Global Call protocol has a built-in function known as gc_BlindTransfer() which does the above three steps and transfer the incoming call to another extension!
This is known a blind call transfer ( so the function name) where the following scenario takes place
1. Calls comes to extension A, suppose from B. Here B is the caller to IVR number A.
2. A hook-flashes B, puts him on hold, by pressing the ON HOOK for fraction of second or as quickly as possible.
3. Now call has to be transferred to C. So, A dials out C.
4. After that A hangs up. And C would be connected to B.
5. A is free again to receive any incoming calls.
But here is the catch, it does not work off the self! It needs proper configuration for getting this function work.
Here are few things one must remember to configure :-
1. In order to use gc_BlindTransfer function, one must use pdk_na_an_io protocol.
2. The pdk_na_an_io.cdp file, which is normally found in Dialogic installation folder and then CFG folder. This file needs to be edited as per requirement. Normally, majority of Indian PBX’s, the following settings are required :-
All BOOLEAN_t CDP_Detect_DialTone = 1
All BOOLEAN_t CDP_ConnectOnNoRingBack = 1
All BOOLEAN_t CDP_Working_Under_PBX_Env = 1
All INTEGER_t CDP_Time_Before_Blind_Dialing_Under_PBX_Env = 3
Rest can be left as it is or to its default values.
3. Store this and restart Dialogic Configuration Manager.
4. Run your application with the function gc_BlindTransfer and it should work!
If you face any problem while following above steps, you may just leave a comment for further assistance, I will surely get back to you!