Registration of Suppliers

Dear Gurus,

We are running SRM 7.02 and MM-SUS Scenario

We are also having Plan-Driven Procurement, Self Service Procurement and Bidding

We want to activate SUS-ROS.

How we have to activate ROS? Supplier Qualification with SRM Server or Supplier Qualification with ERP?

Second Question: Once activated ROS, every supplier has to be created through the Supplier Registration system? No more Suppliers created in ERP (XK01) ?

Thanks

Ezequiel