DoorVaani VOIP Lines provide call transfer capabilities on both incoming calls and outgoing calls. Calls can be transferred to other extensions or other VOIP Lines in the users’ own account or to external lines like PSTN numbers. Calls transferred to external PSTN numbers will be charged a per minute rate as per the current per minute VOIP Call rate published for the transferred number in our VOIP Rates page. Calls transferred to other extensions or VOIP Lines within the users’ own account do not incur per minute call rates. Calls can be transferred to other DoorVaani users’ DID Numbers and VOIP Lines for free without incurring any per minute call cost.
Two types of call transfers:
Both blind transfer and attended transfer are supported by the DoorVaani system. The call transfers are SIP call transfers complying with RFC 5589 standard, and the user should be using a compatible device that has the call transfer facility built in it. One such freely downloadable soft phone known to this author, that comes with both blind and attended call transfer capabilities is Grand Stream Wave for iOS and Android operating systems. Many other popular SIP soft-phones have the call transfer capabilities available in their paid versions if not in the free versions.
Attended Call Transfer: The call transferor first places the call with the transferee on hold, then calls the other party and talks to the other party in private before connecting the call to the new destination. This way the call transferor can ensure that the transfer is successful.
Blind Call Transfer: During a blind call transfer, the call is transferred to the new destination with no intervention of the transferor. The call transferor would not know the result of the transfer like the destination did or did not answer the call.
How to do the call transfer?
For the actual call transfer method the users should refer to their device user guides as these instructions are specific to their device. Basically it involves pressing the “Transfer” button and selecting the type of transfer like Blind or Attended and then dialing the destination number. In a blind call transfer the transferor would get disconnected as soon as the destination number is dialed and the call is placed. In an attended transfer, the transferor would have to either hang-up or press a button to complete the transfer.