North American Network Operators Group
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Re: MAE-East still no generator

  • From: Paul A Vixie
  • Date: Sat Sep 07 23:43:35 1996 
> I realize that the phone world that MFS is part of operates
> differently, but this is networking equipment we are talking about,
> not phone switches, and UPSes are very old tech at this point.

the bottom layers of the network (L2 and below) are mostly telco
stuff and mostly (other than the gigaswitch) prefer DC power.  DC
power is what the box wants internally, and there's a lot less heat
generated by making 5V and 12V out of 48VDC instead of 110VAC or 220VAC.
if you visit a telco switching center and surround yourself with 10
Northern Telecom OC48 racks you should notice how quiet it seems.

> In other words, its silly for them not to have UPSed AC available.

i agree with this but it can't be exclusive.  that's why dec's palo alto
facility has both AC and DC, each of which is UPSed and generatored.
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