Monitoring the Message Flow
BDoc types are used as containers to transport business data. In turn, messages are created on the basis of these BDoc types. The message flow in the CRM server is controlled and monitored by message flow control, which is a key component of CRM middleware. Through this, various evaluations can be carried out.
Process
To monitor the message flow within CRM middleware, choose 
Architecture and Technology
Middleware
Monitoring
Message Flow
in the SAP user menu. The following evaluation options are available:
This explains how to set up the trace monitor, and how to choose the data for display.