ATM Switching with Non-Blocking Single-Queueing Networks A large class of ATM switches is represented by those architectures using a non-blocking interconnection network. In principle a non-blocking interconnection network is a crossbar structure that guarantees absence of switching conflicts (internal conflicts) between cells addressing different switch outlets. Non-blocking multistage interconnection networks based on the self-routing principle, such as sorting–routing networks, are very promising structures capable of running at the speed required by an ATM switch owing to their self-routing property and their VLSI implementation suitability | Switching Theory Architecture and Performance in Broadband ATM Networks Achille Pattavina Copyright 1998 John Wiley Sons Ltd ISBNs 0-471-96338-0 Hardback 0-470-84191-5 Electronic Chapter 7 ATM Switching with Non-Blocking Single-Queueing Networks A large class of ATM switches is represented by those architectures using a non-blocking interconnection network. In principle a non-blocking interconnection network is a crossbar structure that guarantees absence of switching conflicts internal conflicts between cells addressing different switch outlets. Non-blocking multistage interconnection networks based on the self-routing principle such as sorting-routing networks are very promising structures capable of running at the speed required by an ATM switch owing to their self-routing property and their VLSI implementation suitability. It has been shown in Section that a non-blocking interconnection network . a crossbar network has a maximum throughput Pmax per switch outlet due to external conflicts that is multiple cells addressing the same outlet in the same slot. Even more serious than such low utilization factor is the very small load level that guarantees a cell loss beyond significant limits. Queueing in non-blocking multistage networks is adopted for improving the loss performance and whenever possible also for increasing the maximum throughput of the switch. Conceptually three kinds of queueing strategies are possible input queueing IQ in which cells addressing different switch outlets are stored at the switch input interfaces as long as their conflict-free switching through the interconnection network is not possible output queueing OQ where multiple cells addressing the same switch outlet are first switched through the interconnection network and then stored in the switch output interface while waiting to be transmitted downstream shared queueing SQ in which a queueing capability shared by all switch input and output interfaces is available for .
