Dialogic 6.2 - Manual (Page 200)

Making Two-Channel Call Transfers (Tromboning)
November 2009 200
Disconnecting Resources
When disconnecting resources, invert the source and destination
resources so that the firmware responds appropriately.
Due to firmware requirements, when disconnecting resources, invert the
source and destination resources. For example, if you made a transmit
connection from the output slot of Channel 0 to the input slot of network
timeslot 0, where Channel 0 is the source, then you must disconnect
from the input slot of network timeslot 0 to the output slot of Channel 0.
Use the BfvCallSWConnect() function to disconnect connections.
For example, if you made a transmit connection from the output of
Channel 0 to the input of network timeslot 0, where Channel 0 is the
source, then you must disconnect from the input of network
timeslot 0 to the output of Channel 0. The following source code
shows this:
BT_ZERO(args);
args.conn_mode = CALL_SW_DISCONNECT_DEF;
args.src_port_class = CALL_SW_PORT_NETWORK_DEF;
args.src_port_unit = 0;
args.src_stream = 0;
args.src_slot = 0; /* Network Timeslot */
args.dest_port_class = CALL_SW_PORT_CHANNEL_DEF;
args.dest_port_unit = 2; /* Logical DSP Channel Number */
args.dest_stream = 0;
args.dest_slot = 0;
BfvCallSWConnect (lp, &args);
If the application stored the original connection information in a
local variable before creating the two-channel call transfer, restore
the original connection by calling the BfvCallSWConnect function
and referencing the local variable.