The terms described in the following apply for all interface types. In order to be able to explain the common properties of the different interface technologies, this documentation refers to them as follows:
RFC or IDoc interface corresponds to an operation.
An outbound operation is the operation of an outbound service interface, while an inbound operation is the operation of an inbound service interface.
These attributes determine how the operation is used.
● An outbound operation is used by a caller application to send a request message.
● An inbound operation implements a service that is to be called by an application.
The communication mode determines how the messages are to be exchanged.
● In the case of synchronous communication, a response message is expected from the receiver after a request has been sent. Once the request message has been sent, no further messages can be sent until the response to the request has arrived back at the sender system.
● However, in asynchronous communication a (immediate) response is not expected. A sender application can send multiple messages to a receiver in a bundle and then continue executing the application.
The following illustration shows the message exchange between operations depending on the mode and direction of the interfaces.
The pair of communicating operations must have the same mode.