A network system comprises at least one input TNE (10) and one output TNE (11) interconnected by circuits in the network (20). Each TNE in the protection step comprises a traffic selector (22, 23) switchable between listening to the traffic input from a work circuit (13, 14) and listening to the traffic input from a reset circuit (18, 19) and a Split module (21, 24) allowing sending of a same traffic output either to a work circuit or to a reset circuit. Each TNE comprises in addition an agent (25, 26) termed ASTN agent commanding activation and deactivation of the reset circuit and switching of the traffic selector between work circuit and reset circuit. Each of the two ASTN agents can emit an “Activate” message to command activation of the reset circuit and signal to the other agent completed activation of the reset circuit and a “RevertRequest” message for signaling to the other agent the desire to deactivate the reset circuit previously activated, and a “Revert” message for commanding deactivation of the reset circuit after reception of a “RevertRequest” message sent to it by the other agent.