Internet Service Delivery Models: Evolution and Current Issues

This paper presents an overview of the current service delivery models that exist in the Internet, covering also the motivation that triggered the introduction of each model separately. Different Quality of Service (QoS) frameworks like Integrated Services (IntServ), Differentiated Services (DiffServ) and Multiprotocol Label Switching (MPLS) are presented taking into consideration also the alteration of each of the mechanisms proposed by the Internet Engineering Task Force (IETF) over time. We illustrate some important characteristics of the existing service delivery models and open issues for Internet QoS, highlighting the need of research on the measurability of the Resource Reservation Protocol (RSVP).