AbstractThis paper deals with the final goal of the evolutionary process of the public telecommunication networks towards broadband capabilities (B‐ISDN), process which is based on the adoption of the Asynchronous Transfer Mode (ATM).At first, a critical analysis is carried out about the transfer modes which gave rise to the definition of ATM. This analysis makes reference to three different and complementary aspects, i.e. the multiplexing technique, the switching principle and the protocol architecture.Then the current status of B‐ISDN is presented on the basis of the most recent results available from the standardization activity. In particular aichitectural aspects and traffic control issues are conside