When PortalProtect uses an intranet source to receive updates, how is the central location updated?

ActiveUpdate supports downloading the latest components from an intranet machine. Put the update packages on that machine and enable the folder to be shared for other intranet machines to download.

$('#title').html($('meta[name=description]').attr('content'));

When PortalProtect uses an intranet source to receive updates, how is the central location updated?