Re: Here's a new idea:
Bob
It's Monday, so forgive this clarification, but are you asking Tal
to test his scheme on the signaling pairs of a 10/100BASE connection as
well as pins 4/5/7/8 on a 1000BASE-T connection? If not, I'd be curious
if Tal could do this; if so.... then I'm being redundant again redundant
again......
At 10:18 AM 5/1/2000 -0600, Bob Bell wrote:
>
>Tal -
>
>One of the objectives the group stated was to test for
powerablity on the
>same wires as the power would be provided. In addition, it is
desirable
>that the powering and thus the testing be done in such a manner
that the
>signal carrying capability of the wire pairs not be compromised
(this it to
>allow it to work with 1000BaseT. Could your scheme meet these
two requirements?
>
>Bob Bell
>
>At 02:27 4/30/2000, Tal Weiss wrote:
>
>>Hi all,
>>
>>Since this is my first contribution to the forum and I'm not
sure that this
>>email forwarding system works, I'll be brief.
>>
>>I read the different discovery process approaches and I want
to offer
>>something completely different!
>>
>>All of the proposals in the forum are analog by nature, and
lack in
>>"security".
>>
>>I was able to construct a digital
"power-identity-chip", costing less than
>>1$, to be implemented inside the powered-IP-phone. This was
done using
>>off-the-shelf parts.
>>
>>The chip is powered remotely from the switch using 5 Volts
(a simple 5K
>>pull-up resistor does the trick).
>>
>>The power-enabled-switch polls the line for
"power-identity-chip" (this can
>>be done across wires 4,5 or 7,8) and when a phone is
attached the chip is
>>found (CRC protected communication, of course).
>>
>>This chip then tells the switch what it's power requirements
are! (Voltage,
>>which wires, power, MAC address and so on...)
>>
>>The power-enabled-switch then applies the correct power
using the correct
>>wiring!
>>
>>This approach has been tested in the lab and works using
different cabling
>>schemes from more than 200 meters!
>>
>>No false alarms and no misses.
>>
>>I know this is different than all the other approaches
mentioned above, but
>>it works so well I couldn't resist sharing.
>>
>>If more information is needed I'll be glad to supply
it!
>>
>>Tal.
>>
>>--------------------------
>>Tal Weiss
>>Congruency Ltd.
>>23 Hasivim St.
>>POB 7813
>>Petah-Tikva 49170, Israel
>>Email: tal@xxxxxxxxxxxxxx
>>Phone: 972-3-9212322-218
>>Fax : 972-3-9210757
>>--------------------------
>>
>
>Bob Bell
>Cisco Systems Inc.
>801-294-3034(v)
>801-294-3023(f)
>
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