I need a DSL / PRI / *whatever* line to my server(s). How is that handled?
That depends upon your colocation service provider. Some colocation companies have signed exclusive contracts with one or more carriers, requiring you to obtain your dedicated line service from their provider – assuming that the desired service is available. But, if you colo with a carrier-neutral provider, you can order service from any carrier that can run a line to the facility address. Better colocation providers will handle the final internal run of your line for a minimal fee, or for no charge at all.