If you need to develop flexible OData services that serve multiple use cases, it is advantageous to have the application code in the same system in which your SAP Business Suite data resides.
If the SAP Business Suite system in which you want to develop SAP Gateway content is based on:
SAP NetWeaver 7.0, 7.01, 7.02, 7.03, 7.31, you need to install the component IW_BEP.
SAP NetWeaver 7.40 or higher, the SAP Gateway core component SAP_GWFND is installed as standard (includes the same functional scope as IW_BEP) and no further installation is required.
SAP Gateway communicates efficiently with systems in which IW_BEP or SAP_GWFND is installed. These SAP Gateway components transfer all the data to the SAP Business Suite system where the request is processed. Communication between the SAP Gateway system and the SAP Business Suite system is optimized for OData handling so you do not need to develop new remote interfaces for each use case.
SAP Gateway can return both deep (complex) data and flat data. Any metadata such as filtering, paging, and sorting information is passed to the SAP Business Suite system and can be delegated to the underlying database instead of being transferred to the SAP Gateway system. By developing SAP Gateway content directly in the SAP Business Suite system you can maximize the ABAP database capabilities already in place.