Client Role 

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.