An ATM cross-connect system for broadband trials and applications

A prototype ATM cross-connect system has been developed by AT&T in joint collaboration with NTT. The system is intended for flexible broadband trials and service applications. The system supports multiple standard line card interfaces, e.g. 155 Mb/s STM-1, 622 Mb/s STM-4c and 2.5 Gb/s STM-16. These different interfaces can be installed interchangeably into the same physical slots in an arrangement called universal line card slots. ATM cells extracted from different incoming SDH signals are multiplexed to 2.5 Gb/s inside the system for internal cell switching in a core fabric (hierarchical multiplexing). The ATM cross-connect system is based on a growable switch architecture that starts with an 8×8 main frame with a shared-memory switch delivering the best-possible delay-throughput performance and optimal buffering to minimize the cell loss probability. With virtually no effect on performance, the core fabric can be expanded to 32×32, yielding a total system capacity of 80 Gb/s. Further growth to substantially larger sizes is possible. Service-oriented features include 1+1 hitless protection switching, in-service upgrade and compact physical size