An architecture of QoS services for a core Internet network over DTM

The differentiated services (DiffServ) model brings the flexibility of the definition of a variety of QoS services through PHBs (per hop behaviour) and traffic conditioners. It integrates gracefully with the integrated services (IntServ) model, that can have functions of QoS signalling, admission control, channel management, resource estimation and dynamic traffic contract agreement. With this integration we can have a scalable, flexible and dynamic IP core QoS environment. The transport network and switching solution used in the architecture proposed, DIPQoS (DTM IP QoS) architecture, is the DTM, a fast circuit switching technology. It is simple, cost effective and have attractive QoS performance. Four simplex services are defined in DIPQoS: the DSG (DTM strict guarantee), that guarantees the signalled peak rate and delay tolerance; the DGF (DTM guaranteed forwarding), that guarantees a minimum forwarding of packets based on pre-signalled QoS specifications and SLAs (service level agreements) between customer and provider. Another one is the DLF (DTM loose forwarding) that provides a loose forwarding of the packets based on discard priorities and also on guaranteed pre-signalled QoS specifications and SLAs. The last one is the DBE (DTM best effort), like the traditional Internet service, there is not QoS support. The purpose of this paper is to present a functional architecture of QoS services based on DiffServ and IntServ models for a core Internet network over the DTM technology.