Creating RFC Users (SAP CRM) 
An RFC user is required to set up the connectivity between systems.
Logon to the SAP CRM system.
Access the activity using one of the following navigation options:
Call transaction code SU01.
In the SAP CRM GUI menu, choose .
In the User field, enter ERP2CRM.
Choose Create (F8).
Enter the required information:
On the Address tab page, enter the following:
Last Name: ERP2CRM
Function: Default-User for RFC connection
On the Logon data tab page, enter the following:
Password: <your password>
User Type: Communication Data
On the Defaults tab page, enter the following:
Logon Language: EN
On the Profiles tab page, enter the following:
Profile: SAP_ALL and SAP_NEW
Save your entries (Ctrl + S)
Note
The user ERP2CRM has the profiles SAP_ALL and SAP_NEW assigned, which gives full authorization rights. If this authorization is not applicable to your project you can restrict the rights of this user according to SAP Note 0338537.