Configuring Business Systems Using the Local Integration Engine 
All SAP systems based on Application Server ABAP release 6.20 or higher contain a “local” Integration Engine, also when used as an application system. This local Integration Engine enables the system – when used as an application system – to connect to another system via an SAP NetWeaver PI instance (like, for example, the Advanced Adapter Engine Extended (AEX)). This kind of connectivity is also referred to as connectivity based on the proxy runtime. All other systems – either SAP or third-party – connect to the SAP NetWeaver PI using adapters.
The local Integration Engine controls the messaging process (receiving, processing, and forwarding) to and from AEX.
Before configuring business systems with an Integration Engine, ensure the following:
For business systems based on AS ABAP 6.20:
You have installed the XI Add-On in each of these business systems as described in the Installation Guide - SAP Exchange Infrastructure 2.0.
NoteUse AS 6.20 kernel patch level 1253 or higher if you want to generate new ABAP proxies on your business systems based on AS 6.20.
End of the note.The business systems and your AEX are maintained in the System Landscape Directory (SLD).
Connecting business systems with local Integration Engine to the AEX includes the following tasks:
Connecting the ABAP Backend to Advanced Adapter Engine
These configuration task includes:
Creating an HTTP destination to connect the ABAP backend system (business system) to AEX
Creating the RFC destination SAP_PROXY_ESR to connect the business system to an Enterprise Services Repository (to enable proxy generation)
Activating an HTTP Service on the Receiver System
You have to activate an HTTP service on your receiver business system to enable the local Integration Engine to receive XML messages using HTTP.