Delta download of contact person from CRM to ECC

Hi Gurus,

I am new to middleware. I have below mentioned requirement:

I am adding a BP type person in relationship tab as contact person for main BP in CRM. That contact person is replicating to ECC properly. However, when I see the corresponding ECC customer's contact person in xd03 transaction, the address what i gave in crm for that contact person in CRM is not updating in "Business Address" for that contact person in ECC. I need to achieve this fucntinality.

I have deregistered the R3A* queue and started dubugging the code. However in am not able to find the exact RFC FM call from main FM BUPA_MWX_BDOC_DOWNLOAD_R3A to ECC for contact person creation. I need the place from where the control goes from CRM to ECC, so that i can do further analysis.

Please help..

Thanks   in advance

Bhushan