Abstract: The switching network (SN) includes a plurality of intercoupled switching units (SU) and a communication path (VP) established by a path set up cell (PSUC). In the switching units (SU) the communication path is routed through the cell marked with a first tag (ID) included in the path set up cell (PSUC), thereby providing the possibility for a second communication path to be set up later by a second path set up cell including a second tag (ID, DISL1) with the same value as the first tag (ID), in such a way that it does not cross the first mentioned communication path (VP) or that it crosses it at most a predetermined number of times, as indicated by a counter (CO, C1) also included in the second path set up cell.

Abstract: A multiple-ring communication system is disclosed wherein each node of the system is adapted to collect information on the status of the system. Receiver/transmitter equipments of each of the nodes are able to transmit ring test messages on the rings, the destinations of which are the node itself. Processing equipments control the receiver/transmitter equipments of the node and are able to check the receipt or absence of receipt of the ring test messages prior to possibly executing reconfiguration operations. Receiver/transmitter equipments of each of the nodes are also able to transmit neighboring node test messages on the rings, which upon receipt by the receiver/transmitter equipments of the neighboring nodes normally give rise to the transmission to the node of node test reply messages on rings different from those on which the neighboring node test messages were transmitted.