We present a detailed analysis of the bandwidth requirements in a network-on-chip at high and low voltages. We propose mechanisms to maintain the functionality of a system-on-chip despite the presence of failures in the network-on-chip used to connect its components. Our mechanisms alleviate failures in the links and/or the connected buffers, and allow voltage scaling for the network. Our best mechanism allows reliable network operation well below 500 mV while reducing power by more than a factor of 5 and energy by 28% compared to a baseline without fault-tolerance mechanisms.