Summary:ASTERISK-21336: Bridge API Enhancements - add externally initiated attended transfers
Reporter:Matt Jordan (mjordan)Labels:Asterisk12
Date Opened:2013-03-29 09:15:51Date Closed:2013-05-28 09:54:03
Status:Closed/CompleteComponents:Core/Bridging Core/Channels
Versions:Frequency of
must be completed before resolvingASTERISK-21520 Bridge API Enhancements - implement attended transfers in chan_sip
is related toASTERISK-21457 New SIP Channel Driver - enhance basic REFER support to handle SIP attended transfers
Description:Please see the [Bridge Construction|http://svn.asterisk.org/svn/asterisk/team/group/bridge_construction/] Team project for the current status of this work.

Once we have the ability to gain control of a channel (see ASTERISK-21334), we should be able to implement {{ast_bridge_transfer_attended}}. This would let a higher level application or channel driver request that a channel initiate an attended transfer.

Attended transfers are obviously more complicated then blind transfers. A few things need to be thought through:
* Unlike a DTMF initiated transfer inside a bridge, an externally initiated attended transfer will typically consist of 4 channels in 2 already established bridges. Thus, the {{ast_bridge_transfer_attended}} is most likely less about initiating a transfer then it is about taking those four channels and merging their bridges appropriately to complete the attended transfer.
* Optionally, an attended transfer operation may want to also simply merge 3 of the 4 channels into a single bridge, creating a multi-party bridge.
* An attended transfer will need to potentially update roles on the various channels (who is the caller/peer needs to be set appropriately)