IP QOS: traveling in first class on the Internet

The concept of quality of service-that is, the network capability to provide a nondefault service to a subset of the aggregate traffic-has now entered the IP lexicon. The author surveys the history of this development from the Internet's original passenger-class-only, best-effort protocol suite. He concludes with a review of the current Internet Engineering Task Force's efforts in the Differentiated Services (DiffServ) working group.