The power ratings on the label of a power brick are the ratings that were used when the power supply was tested by UL for safety. They may or may not have anything to do with the actual power draw of the modem. The reason for the higher input power rating, other than the efficiency loss of the circuit, is that UL requires the unit remain safe during fault conditions, such as a shorted output or a component failure within the power supply. Under these conditions the current draw can be higher, than under normal operating conditions. Anyway, as I sit here typing this my Killawatt meter on my HT1100 modem shows it is drawing 23W at 120V input.
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