It's no harder to tell what priority or service level a packet wants than it is to know where it wants to go. If you can forward it at all, you can forward it at the appropriate service level. Similarly, it's not hard to know how big a packet is, but it's a lot harder to decide how to fairly manage two packet streams when one consists of a series of short packets and the other consists of a series of long packets. Does fairness mean that every packet competes with every other packet regardless of size, or does it mean that every stream gets to consume an equal amount of bandwidth? This is the sort of question that network engineering depends on, and without a firm answer it's impossible to run a network, let alone a fair, democratic, and non-discriminatory one. Not that I expect a response, but consider how your answer would compare to something like admission decisions at a university. Does every applicant have an equal chance of acceptance, or are some more equal that others on account of their grades or their ethnic background or their gender. Is 'equality" a simple policy, or does it need some creative interpretation?