Business Communication 

There are several types of message exchange within a PI landscape, all involving a central Integration Server. They are depicted in the following figure, each with the required type of protocol (XI or non-XI) and user for authentication.

 

The message exchange between business systems or business partners can be separated into the following communication parts with several communication variants.

●      Sender to Integration Server

There are four types of communication (outlined the figure above) by means of which an Integration Server receives a message:

○       The sender (s1) is an associated ABAP business system working with ABAP or Web service proxies that send messages by using the XI protocol.

○       The sender (s2) is a Java proxy running on an associated Advanced Adapter Engine that sends messages by using the XI protocol.

○       The sender (s3) is a system that sends messages in a non-XI protocol using an associated Advanced Adapter Engine.

○       The sender (s4) is another Integration Server or a Partner Connectivity Kit (PCK) that sends messages by using the XI protocol.

●      Integration Server to receiver

There are four analogous types of communication by means of which an Integration Server sends a message to the next receiver:

○       The receiver (r1) is an ABAP business system working with ABAP or Web service proxies that receive messages in the XI protocol.

○       The receiver (r2) is a Java proxy running on an associated Advanced Adapter Engine that receives messages in the XI protocol.

○       The receiver (r3) is a system that receives messages in a non-XI protocol using an associated Advanced Adapter Engine.

○       The receiver (r4) is another Integration Server or a PCK that receives messages in the XI protocol.

●      Sender to Advanced Adapter Engine

○       The sender (s3) is a system that sends messages in a non-XI protocol.

●      Advanced Adapter Engine to receiver

○       The receiver (r3) is a system that receives messages in a non-XI protocol.

Concerning users for authentication, U=d(S) denotes that the user is obtained by means of an Integration Directory configuration, whereas U=c(S) means that the user is obtained by any other configuration in the sender system. The latter implies that the identity of the user in the sender system is not propagated to the Integration Server. However, PI also allows the user context of a message to be propagated unchanged from the sender to the receiver. More information: Propagating User Identities at Service Users for Message Exchange.

Depending on the configuration, the following further communication variants can be applied for obtaining additional services for message execution:

●      For receiver pre-identification or maintenance of value mappings, an ABAP sender proxy (case s1) may need RFC access to its Integration Server by using destination AI_INTEGRATION_SERVER.

●      The Integration Server may execute a mapping service, in which a JCo RFC communication takes place by using destination AI_RUNTIME_JCOSERVER.

●      The Integration Server may execute digital signature services by using the security Web service WSSPROC of its AS Java.

●      IDoc metadata may be read from an IDoc business system by using SM59 destinations maintained with transaction IDX1.