VC3/VC12 Use the VC3 or VC12 subtab to provision the line parameters on the cards or ports. Item Description VC LO Displays the VC3 or VC12 number. Enable IPPM Allows you to enable intermediate path performance monitoring (IPPM). Apply Applies changes made to the fields in the tab. Reset Cancels any changes to the tab and returns the fields to their last-saved settings. Help Displays context-sensitive help.