What program populates the iSupplier for forecast and orders.

We are on R12.1.3, do not use Collaborative Planning responsibility but do have all the setups done for ASCP and iSupplier.  VMI is not used.  Can you please advise a couple of things regarding data population of forecasts and orders;

1)  Which program populates the data into the iSupplier portal for Forecast and Orders?  Would that be the 'Publish Order Returns/Forecast' from Oracle?  It appears that that program grabs all the changes from Data Collections run, also--to keep the data current in iSupplier, I would assume it would depend on how often that program runs?  We want to make sure the iSupplier Portal mirrors the Supply Chain Workbench as much as possible.  What governs if safety stock is sent to the portal?