In its client role, the SAP Web Application Server creates HTTP requests in an ABAP program, and processes the responses.
If the SAP System is the client, that is, if a work process wants to send a request to the Internet, this procedure works in reverse.
The work process writes the data to be processed into an MPI and sends the request to the ICM via a network connection, using TCP/IP. The ICM then processes the data it receives from the MPI and writes a response back into the MPI. For a detailed description of the ICF process, see Interaction Model.