Outbound Processing 
Use
In outbound processing, document data is written to IDocs and sent to the receiving system.
Features
The message can be sent from the application to the IDoc interface along two different paths:
indirect path using Message Control (MC): a series of conditions are checked to "find" the message. If one of these conditions is fulfilled, the message that was "found" is forwarded to the IDoc interface via the corresponding Message Control record. This condition technique also allows the Message Control module to find and send more than one message. For further information on MC see
R/3 library
® Cross-application functions
® Message Control.the
direct path from the application to the interface. Here, the application generates an IDoc which is transferred to the IDoc interface via the function module MASTER_IDOC_DISTRIBUTE.
The IDoc interface can send the IDocs to the receiving system along different paths (receiver ports). Port selection also depends on the receiving system and the hardware used for the installation. Please read the information in the following section
Communication with Older Releases