A system comprises a plurality of processing modules, one of which is designated to be the primary processing module and the others are designated to be secondary processing modules. During operation, state is maintained in the primary processing module and at least one of the secondary processing modules....http://www.google.fr/patents/US7382724?utm_source=gb-gplus-shareBrevet US7382724 - Automatic switchover mechanism in a network device
Automatic switchover mechanism in a network device
