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@congruency.com
>>Phone: 972-3-9212322-218
>>Fax : 972-3-9210757
>>--------------------------
>>
>
>Bob Bell
>Cisco Systems Inc.
>801-294-3034(v)
>801-294-3023(f)
>
*************************************
"At the end of the day... the most committed win!"
James M. Polk
Sr. Product Manager, Multiservice Architecture and Standards
Enterprise Voice Business Unit
Cisco Systems
Dallas, Texas
w) 972.813.5208
f) 972.813.5280
www.cisco.com
Cisco Systems Inc.