RE: Here's a new idea:
Geoff
I'll take that challenge -- however, because I don't work for this
company, I cannot claim with a paycheck that it is accurate: IBM
apparently has 300,000 users of STP that doesn't have 8 conductors. I
understand that Ethernet is either installed or planned throughout the
company (again, only rumors)...
But this is *all* of one very big customer.
Another large company that I believe is migrating from STP-TR to
Ethernet is Taco Bell. I don't know how many users they have -- but they
aren't small -- and again, this represents *all* of a customer.
At the end of the day, do I think it's a large number of
installations that are affected by this? No. But I don't see why yet, we
shouldn't attempt to include everyone. Putting DTE Power on the 4
signaling pairs accomplishes this. As without those 4 pairs -- you don't
have any Ethernet.
If the Engineering exists and can be proven to work utilizing the
signaling pairs -- why isn't that the mode this committee
pursuing?
This is what I'm scratching my head about.... at least ever since
York.
At 12:40 PM 5/2/2000 -0700, Geoff Thompson wrote:
>James-
>
>For every soapbox there is yet another.
>Both 802.3 and EIA/TIA TR-41/42 Standards groups have been
preaching for
>well over 5 years that all RJ-45 installations of "generic
cabling" should
>be star wired and terminate all 4 pair in a single
RJ-45.
>
>This was done for several reasons:
> 1) To
make the cabling plant generic (i.e. application independent)
> 2) To
provide a uniform platform for future applications
> 3) To
provide a well characterized transmission environment
>
>Customers who did not do this were at risk of losing the
capabilities of a
>generic cabling plant. In particular for number 2 the future
applications
>are (at this time and from my point of view) 1000BASE-T and DTE
Power.
>
>As for splitting 4 pair to 2 outlets, that works fine for
10BASE-T. It is a
>bad idea in terms of a 100BASE-T transmission system. The
crosstalk from a
>10BASE-T into some of the older implementations of 100BASE-T can
be disruptive.
>
>As to your assertion that the 2 pair split-out represents
"many" and STP
>Type 1 & 2 installations represent
"Lots"...
>
>Sorry but we need better information than that. How about some
quanitative
>input as to number of installations that are real-live
candidates for
>DTE-Power applications and the percentage of the installed base
that they
>represent?
>
>Geoff
>
>At 03:29 PM 5/1/00 -0500, James M. Polk wrote:
>Dan
>
>I believe there will be a greater impact on *not* engineering
this on the
>Signaling pairs. Both 10 and 100 Ethernet utilize only two
pairs, not 4
>pairs. So a minimum implementation of Ethernet is pairs 2&3,
and nothing
>knows the wiser. Having power on those signaling pairs satisfies
this
>minimum implementation. Any other implementation should ask the
following
>questions:
>
>How many customer sites have split off their 4 pair cabling for
an
>additional station? Many
>
>How much STP Type 1 and Type 2 is there installed? Lots
>
>The cost of re-cabling these sites is significantly greater than
the cost
>of the new equipment for VoIP and other such implementations
that will
>utilize this NEW power capability.
>
>This will prevent the adoption of this committee's effort to
whole customer
>sites at a time -- which I've never thought was a good
philosophy, but
>seems to be what's going on here, IMO. This seems like a very
exclusionary
>position, not inclusionary (which is how a standard should
be).
>
><off soapbox>
>
>for now.....
>
>;-)
>
>At 12:39 PM 5/1/2000 -0700, DOVE,DANIEL J (HP-Roseville,ex1)
wrote:
> >
> >Hi James,
> >
> >It occurs to me that the detection method is irrelevant
to
> >1000BASE-T operation as the link will not be up at the
time
> >of operation. However, the issue at hand is whether you
can
> >inject power at a mid-span in a way that is compatible
with
> >1000BASE-T signalling requirements.
> >
> >There have been some votes on this subject and my
recollection
> >is certainly not the best thing to rely upon, but I
recall
> >that 10/100T is a MUST while 1000BASE-T is a WANT.
> >
> >Using pins 4,5 and 7,8 minimize the potential impact on
10/100T
> >but would likely have an impact on 1000BASE-T.
> >
> >There are studies underway to understand just how much
these
> >impacts are and whether they will exclude 1000BASE-T
operation.
> >
> >Regards,
> >
> >Dan Dove
> >___________
_________________________________________________________
> >_________ _/
___________ Daniel
Dove Principal Engineer
__
> >_______
_/ ________
dan_dove@xxxxxx LAN PHY Technology __
> >_____
_/
______ Hewlett-Packard
Company
__
> >____ _/_/_/ _/_/_/
_____ Workgroup Networks
Division
__
> >____ _/ _/ _/
_/ _____ 8000 Foothills Blvd. MS
5555
__
> >_____ _/ _/ _/_/_/
______ Roseville, CA
95747-5555
__
> >______
_/ ________ Phone: 916 785
4187
__
> >_______
_/ _________ Fax : 916 785
1815
__
> >__________ _/
__________________________________________________________
> >
> >-----Original Message-----
> >Sent: Monday, May 01, 2000 10:11 AM
> >To: Bob Bell; tal@xxxxxxxxxxxxxx;
stds-802-3-pwrviamdi@xxxxxxxx
> >Subject: 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)
> >>
> >
> >
> >*************************************
> >"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
> >
>
>*************************************
>"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
>
*************************************
"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