Communication Component Types
You store configuration data for the runtime of integration scenarios in the Integration Directory (ID). This data includes representatives of the sender and receiver systems of messages.
There are two types of senders or receivers of a message in SAP Process Integration (PI).
The communication components group the following object types:
- Business system
- Business component
Communication components in the form of business systems refer to business systems in the System Landscape Directory (SLD) and are imported from there.
To execute the import, select the Communication Component node (in most cases, on the Objects tab page) of the ID and select the Assign Business System option using the right mouse button. The list of business systems in the SLD for which there are currently no assignments in the ID displayed.
Hint
If you create a new business system in the SLD, you may have to clear the SLD data cache in the ID so that you can see the new business system in the list. To clear the SLD data cache, choose Environment → Clear SLD Data Cache.
SLD Interface for the ID

Business Systems and Business Components can be the sender and receiver of messages.
Note
The yellow line symbolizes, that this functionality is performed in 2 different tools.
Information that specifies how the sender or receiver communication components can be contacted must be stored in the ID. In addition, a message must either be converted into a format that the target system understands or transformed into a process integration XML message that is then delivered to the Integration Server. This task is performed by an adapter and the configuration object in which you define the adapter for the inbound or outgoing message is called the communication channel.
Communication Channel

The main tasks involved in creating a communication channel are as follows:
Select the communication component.
Specify the communication component for which you want to create the communication channel (for example, the business system).
Enter the name.
Enter the name of the communication channel. If possible, choose a name that is self-explanatory, for example, RFC_Sender.
Select the adapter type.
Specify the connection details (for example, file adapter for file access) and whether it is sender or receiver.
Select the adapter engine and the protocol.
In addition to the Central Adapter Engine (CAE), you can also have other local adapter engines. You need to enter details for the transport and message protocols, such as Exchange Infrastructure (XI) 3.0, Network File System (NFS) or File Transfer Protocol (FTP), and so on.
Enter the adapter specific parameters.
You enter additional details for each adapter (for example, the target directory for file receivers).