The paper aims at providing a comprehensive picture of the new set of ATM-layer services defined in parallel by the ITU-T and The ATM Forum, outlining the potential benefits that can derive, both to users and network service providers, from the availability ofthese new functionalities in an ATM-based network.Terminological differences between the ITU-T and ATM Forum documents are compared and clarified and the approaches to the use of quality of service (QoS) parameters and classes are discussed. The so-called Service Categories (using the ATM Forum nomenclature) are Constant Bit Rate (CBR), Variable Bit Rate (VBR), Available Bit Rate (ABR) and Unspecified Bit Rate (UBR).The ABR is the newest and the one raising major discussions, as specific congestion control mechanisms, which do represent a real innovation in the ATM framework, have been defmed for its support. The paper therefore introduces the ABR service in some details and discusses some still open issues and utilisation perspective.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.