Foreword This draft European Telecommunication Standard (ETS) has been produced by the Network Aspects (NA) Technical Committee of the European Telecommunications Standards Institute (ETSI).and is now submitted for theUnified Approval phase of the ETSI standards approval procedure. NOTE: With respect to edition 1 of ETS 300 301@ this ETS provides the definition of additional traffic parameters besides the Peak Cell Rate@ namely@ the Sustainable Cell Rate and the Intrinsic Burst Tolerance. It provides also the definition of additional ATM layer Transfer Capabilities suitable for statistical allocation of network resources@ besides the basic transfer capability based on peak allocation (Deterministic Bit Rate transfer capability)@ namely@ the Statistical Bit Rate transfer capability@ the Available Bit Rate transfer capability and the ATM Block Transfer capability.