I think the OP is aware of that, but seeing as on FTTC the PSTN service is routed through the cabinet DSLAM is asking if power failure and battery exhaustion there would cause PSTN failure.
Similar in concept but not technically to the way a DECT phone won't work.
Or is the connection at the DSLAM somehow fail safe and would allow the exchange-provided power to pass through in such circumstances?
The indispensable man or woman passes from the scene, and what happens next is more or less the same thing as was happening before.
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