Sets of communication modules each have a pair of ring-channel ports for a ring-configured channel in a network, a peripheral device port for peripheral device data, and dual-ring ports for an inter-ring channel for the pair of modules. First and second ones of a set of communication modules send duplicate data packets on their respective first and second rings. Responsive to duplicate data packets arriving via the rings at first and second modules in a next set within a predetermined time interval of one another, each of the next modules transmits its ring-channel received data packet out a downstream ring-channel port. Responsive to one of the duplicate packets arriving at the DRP of a module a predetermined time interval before arriving at a ring-channel port of the module, the module sends the corresponding packet received at the DRP out its other ring-channel port and its peripheral device port.