Re: Gigabit over 150 ohm STP
Dan
I'm not stating there should necessarily have been a decision in 'my
way' already -- I'm merely reacting to what appears to be a decision that
the other way has already been decided. You claim it has not. That's fine
with me.
At 09:22 AM 5/4/2000 -0700, DOVE,DANIEL J (HP-Roseville,ex1)
wrote:
>
>James,
>
>Just to emphasize my concern with your argument, I will use
a
>bit of rhetoric.
>
>It would seem that the IEEE 802.3ab made a big mistake by
focusing on a
>4-pair, CAT-5 scheme rather than a 2-pair STP method of
transmission. How
>could the IEEE have made such big mistake? What will IBM and
Taco Bell do if
>they ever want to migrate to Gigabit?
>
>As Geoff said, the DTE-PWR committee chose to use 4 pairs
because
>they have been proscribed by the EIA/ISO for years now and
anyone
>who is specifying their building infrastructure with an emphasis
on
>application flexibility has been using that approach.
>
>We have not decided which pairs to apply power onto yet. This
>is subject to study, presentation, and debate. I believe that it
>is intuitively obvious to anyone that putting power on the
"unused"
>pairs will provide less risk to 10/100T applications than using
the
>data pairs. The subject of debate should and will be "How
much less
>risk?" If it is zero, then your points will gain relative
weight. If there
>is a measureable impact on 10/100T operation (our primary
objective) then
>your points will lose relative weight. I expect that we will see
this risk
>quantified by the next meeting.
>
>Best Regards,
>
>Dan Dove
>HP ProCurve Networks
>
>-----Original Message-----
>Sent: Wednesday, May 03, 2000 10:13 PM
>To: Geoff Thompson
>Cc: stds-802-3-pwrviamdi@xxxxxxxx
>Subject: 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
>
>
*************************************
"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