Dialogic 6.2 - Manual (Page 196)

Making Two-Channel Call Transfers (Tromboning)
November 2009 196
Figure 14 on page 196 shows the connections required to configure
the echo canceller on a channel during a two-channel call transfer
while recording from person A. The application sends the final echo
cancelled data up to the host for recording.
Figure 14. Required Connections for Echo Cancellation
Channel 1
In Ref_In
Out
In
TSlot 0
Person A
Host
Out Ref_Out
Channel 1
In Ref_In Out Ref_Out
In
Out
TSlot 1
Person B