Historically the need to segregate fibre-channel traffic and have the option to prioritize frames and flows has not been high on design agenda of most of the companies I had under my eyes. Most often if the need is there to differentiate between different levels of importance between the various business applications you’ll very often see that additional equipment is purchased and the topologies are adjusted as needed. This obviously works well however when the ratio of capex vs opex is out of balance but the business is still retaining the need for your applications to be separated in order of criticality, you need to consider other options. As in the IP networking world Fibre-Channel has a similar functionality which has been in the FC standards for a long time but only recently has been introduced by some vendors.