Nathan Ward wrote:
On 1/07/2008, at 11:47 AM, Andrew Hooper wrote:
Heck you can even get 3000AH 12V Disposable Cells
these days. And no
not make a mistake. That is 3KAH. When you work that into what a
draws (1.2AH) or there about that's a heck of a long time.
Even the new generation deep cycles these days have a cyclic life of
to 10 years.
"Routers" require 1.2A at 12VDC?
My little Soekris boxes draw that, roughly, or at least that's what
they say they need from a PSU. Anyway, same ballpark. They are not big
routers, infact, they are very very small routers. They do no have fans.
Indeed. I can cite a few examples of router power consumption which are
vastly in excess of that. Any metro Ethernet operator is likely to be
using something similar in the core/aggregation, at the least.
Alcatel-Lucent 7x50: between 50A and 175A per chassis, at -48V DC.
Juniper T-series: between 60A and 175A per chassis, at -48V DC.
Juniper M-series: between 20A and 130A per chassis at -48V DC.
Juniper MX-series: 5.1KW per chassis.
Cisco 7600 series: 40A+ per chassis at -48V DC
Cisco CRS-1: 11KW per shelf, up to 72 shelves.
Telcos tend to use DC, since most of the existing deployed plant is
based around supplying DC power.
Edge devices, depending on the size of the edge involved, can be
anywhere up to 40A or so - I've seen quite a few edges that use 7600s
:). As Matthew pointed out, most of Vector's edges *used to be* Cisco
Cat 2900/3500/3750, which typically consume more in the 250W-750W
region. The problem IME with several operators has been the maintenance
of hundreds/thousands of UPS and batteries. This is not a solution
which scales very well, but is pretty much required.
Two things that operators (both the retail service providers and the
metroE operators) could do to ensure continuity of service:
1) Stop providing active edges at customer sites - simply handoff GE via
optical services and be done with it. Bring in more fibre to the
customer site if you need density.
2) Find a customer with key infrastructure, and place the equipment on
their UPS/genset. ISTR that Citylink used to do this where they could;
and certainly when I was at Maxnet we put the Vector CPE on our UPS'.
Interestingly, telcos that deploy SDH mux equipment to customer sites
tend to install them with a full 48V DC plant, including rectifiers and
often inverters. Perhaps the MetroE guys need to take a look at how the
telcos have done it in the past, if they are wanting to meet that 'five
nines' of telco-land?