ISU Business partner Change Activity not replicated to SAP CRM

Hi All,

We have a SAP CRM and SAP ISU systems integrated environment. Whenever there is a change in the Business partner information in ISU system an activity needs to be created.For instance xyz, Now the same activity should be logged and the record must be accessible from SAP CIC interface. I am interested in understanding the technical information - interfaces, classes, RFC and tables involved in this process. I tried to debug but it leads to many interfaces and function modules .

1. How are the activities recorded and replicated to CRM system.
2. What are the function modules which are used in replicating this information to CRM system?
3. Is there any scope of ALE IDOC model in this process?
4. How can I see the or know if there are any background jobs related to this process?

Thanks,

Pavan