scope:

The purpose of the present document is to provide specifications for ATM equipment to be used in the ETSI region. These specifications seek to define the processes associated with ATM rather than specific equipment types. Such specifications will ensure compatibility between equipment by identifying which functions within a process are mandatory for interworking and which can be considered as truly optional. It is not the intention to prevent manufacturers or procurers from following an alternative specification, but the consequences should become clear from the present document.

The ETSI ATM Equipment specification will be in two parts. The first part (the present document) being more conceptual, producing a list of functions and processes and some guidance to the ITU model and the ETSI functional model. The second part (EN 301 163-2-1 [18]) is a formal representation of transfer and layer management functions in the form of a library of atomic functions. This will provide flexibility since many equipment types may be defined by using these atomic functions in different combinations.

The specification will take advantage of the work done in ITU but will take the work further with an ETSI view. This means: the identification of ITU options that has to be mandatory in the ETSI region, deletion of options not required for the ETSI region, creation of new or revised descriptions where necessary, identification of guideline or benchmark performance parameters for classes of equipment.