QoS and differentiated services in a multiservice network environment

Service differentiation is a prerequisite for satisfying the variety and range of quality of service (QoS) demands placed on an integrated services network. This paper explores different technology options for an integrated services infrastructure and analyzes them for their ability to satisfy multiservice requirements such as those needed for virtual private network (VPN) intranet applications. The analysis draws on concepts from Internet protocol (IP) and asynchronous transfer mode (ATM) networks; their interworking, as in the multiprotocol label switching (MPLS) and multiprotocol over ATM (MPOA) approaches; and switching, routing, and signaling. A QoS spectrum relating the many traffic control schemes to the different classes of service is a contribution of this paper. Evolution paths from an existing infrastructure of IP routers offering best‐effort service to an infrastructure offering differentiated and guaranteed services are identified. The paper includes a proposal for supporting differentiated and guaranteed services in the MPOA framework. In this paper, all traffic offered to a network domain is assumed IP.