Re: [802.3af] inadequate power PSEs
Hi
I am with Goeff on the plug and play issue if we open this up to
labeling
then everyone will get 'creative' about going around the power supply
issue
but not by doing the right design to account for power - but by shipping
1/2 the wattage needed and claiming compliance .... Then again
chances
are Mike will come up with argument that tempts me to reconsider.
to me that fact this is NOT too clear, and is debatable, proves
that
the risk of it making a mess are great.... my 2c anyway....
also we run hard to 'graduate' and we seem to go back and open up
subjects that
were sweated for months before.. just because we can not recall the
details:
classification and class zero though not too sophisticated gave us a
start
for hooks into the phy later, a back up plan for discovery that was
plagued with
low current suseptibility to noise, and leackage of diodes and power
FETs.
these were real concerns that we tackled for months.... I shall
invite
Rick to refresh our memory ....
also we have increased the detection signature to a much wider value
than
the one the hazard matrix was based on... so can we stop fixing 'unbroken
things'
and move on....
at the end of the day, it may be hard to tell the exact right thing to
do.
but the is what voting is for....
rk
At 10:49 AM 1/23/2003, Geoff Thompson wrote:
Folks-
I think I will stick to my position. Steve's arguments for the other side
below only (in my opinion) prove my point.
20 AMPs in the guest bathroom is just fine. It corresponds to our full
power situation. You can run an iron or an electric heater off a 20 AMP
circuit. If you try to do both then you deserve to have the breaker trip.
The breaker BTW, these days is a GFI in the bathroom. You don't have to
go down to the basement to reset.
The cigarette lighter socket in Steve'car is the 2nd socket. There is
still a high amperage socket for the lighter within reach of the driver
and the car came with a lighter in that socket. When additional socket
started appearing in cars it was in a mature socket situation and nobody
(well, there was probably some fool somewhere) was looking to add more
cigarette lighters, they were looking for a place to plug in their cell
phones. The bulk of the market understood the situation quite well.
Our situation, on the other hand is somewhat different (Opinion
piece).
1) The
market we are approaching is used to wall warts. The market expectation
for those is that they are absolutely not interchangeable between
products. Our goal is that DTE Power just works everywhere. Kill wall
warts!
2) I am of
the opinion that if we had not had Auto-Negotiation for 10/100 Ethernet
then 100BASE-TX would have been a bust, or at least a slug. This would
have been true even if product had Auto-Negotiation but what was sold was
like to not be able to find a common operating mode between the 2 ends.
One of the reasons (albeit probably a minor one) that 100VG-AnyLAN failed
was that you had to manually configure it to match the two ends of the
wire. It wasn't plug and play.
Therefore, I am still of the opinion that we should position the front
end of the market so that everything just works. When folks
understand it a little better, a couple of years down the road, then we
can back down.
Geoff
At 12:09 PM 1/23/2003 -0500, Steve Jackson wrote:
... pardon the tongue-in-cheek title ...
This issue really has me torn.
Mike's rationale is great, and Geoff's concerns are also 110%
valid.
I'm going to speak up, since I haven't for a long time. I support the
low-power-warning label "deal" for the following reasons:
1. Power-limit-at-the-socket paradigms are a fact of life in our consumer
society. Having a label stating this is a bonus that isn't always
offered; my car's cigarette lighter socket, which cannot source enough
power to perform that function, is so labeled. The AC outlet in the guest
bathroom can't source 20A, and isn't labeled. The circuit breaker is.
Mike cites some .3 precedent but that isn't a concern to me. A 4 watt
port is OK as long as you tell me about it, and besides, that's why they
make polyfuses.
2. I didn't like the classification idea from the get-go, which, as
you'll recall, started out as an optional feature. Having this 'feature'
opens up (encourages) the possibility of deployment of poorly-architected
.af systems, defined by me as those not capable of delivering
battery-backed-up full power on all ports. Now that someone WANTS to sell
such a system ON PURPOSE (even worse than the power allocation scheme) I
say, go ahead. As long as it's labeled. Make sure the warning-label color
is specified as bright yellow; caveat emptor. I also think that
power-allocated ports ought to be so indicated by a blinking yellow
port-status LED, but I never thought I'd get anywhere with such a
proposal.
3. Oh, yeah: I mentioned power-allocated systems in #2. If we allow them,
we have explicitly already allowed what Mike wants. I admit ignorance of
the discussion-goings-on since I no longer can attend the .af meetings,
but, heck. Why the fuss?
Nomex suit on.
/steve