RE: Signal vs. Idle debate (was: Here's a new idea)
I too will answer concisely below
At 10:28 AM 5/8/2000 -0700, DOVE,DANIEL J (HP-Roseville,ex1)
>(Hi All, I am re-sending this with the comments )
>(clearly identified.. my previous response to the)
>(HTML format did not come out readable. Sorry )
>( Dan Dove )
>I will try to address your points consisely.
>> -----Original Message-----
>> Sent: Friday, May 05, 2000 11:20 AM
>> To: DOVE,DANIEL J (HP-Roseville,ex1);
>> Subject: RE: Signal vs. Idle debate (was: Here's a
>> Dan (and all)
>> Comments inserted
>> At 03:39 PM 5/4/2000 -0600, DOVE,DANIEL J
>> >Hi Norman,
>> >I have a few issues with the direction you are
>> >discussion so far. Let me explain.
>> >> If the market is growing very rapidly,
then existing owners
>> >> of (what will soon
>> >> be) absurdly bulky and expensive
switches will be small
>> >> fraction of the total
>> >> Ethernet market, and catering to those
old switches with
>> >> add-on boxes to
>> >> supply power will be a niche
>> >On the other hand, we are in the business of
>> >today to solve problems, not create them. There
are plenty of
>> >switches being sold today that support VoIP but
>> >power because there is no standard for it. Are
>> >"old, absurdly bulky or expensive"? I
don't think so. Some of
>> >them are highly integrated and very cost
effective. I could
>> >give you examples but I think you know I am
>> Dan -- let's get a little realistic, here. We're not
>> talking about
>> software to be downloaded to existing equipment to
>> advantage of this
>> new capability. DTE power means that customer has
>> new technology.
>> That means new equipment to buy (in this case).
>> is a fact.
>OK. A customer can buy an HP4000 today that does not
>power but supports VoIP. They can buy a power-insertion
>panel (when the standard is defined) and a phone, and they
>now fully operational without ripping out their switch. Is
>clear? This model works for many other switches that are in
I'll bet that powered patch panel cost more than that switch, or at
least very close if with a high density of ports on both
>> Devices that expect power on either pair are
>> built -- therefore
>> just bought -- therefore nothing is old or existing
>> regarding this coming
>> Standard. If the switch manufacturers cannot build a
>> switch module with
>> power on that module -- shame on them.
>The question is not "IF they can do it", it is
"should they be
>forced to do it"? The committee decision to require
>support says "no".
I'm not stating that the powered patch panel be dropped. Sorry I you
read my emails that way.
>> Companies are already doing it and those that
>> sell too much
>> product. Period. This is a fact.
>I disagree. I believe that those who apply power at the switch
>burdening the cost of the switch for a limited number of
>applications. Those who rely on a patch panel power
>actually allowing the customer to determine which ports to
provide power to
>and keeping their switch investment optimized.
>Isn't this element of the debate moot? The committee has already
>that mid-span insertion is a "must".
Point above -- powered patch panels should be specified.
Question though, in the Telecom closet that your office or cube gets
Ethernet connectivity from.... how much room is there for an additional
co-located Powered Patch panel? It could end up needing to be one for one
ports to the number of desktop computers you have in your facility. Do
you at HP have rack space for all those patch panels....
I honestly don't know your situation.... I just know a lot of Cisco
customer situations (which are rather numerous)
If it's from the switch that is built of the same size -- rack space
isn't an additional *very real* burden on those customers.
>> As a point of reference towards past work the IEEE
did: 802.1p/q made
>> everyone purchase new Ethernet switches because no
>> built their
>> existing Switches with the ASIC capable of those
>> bytes to the
>> Ethernet Header. This too is a fact. Period.
>But people ARE providing VoIP capability in their current
products and their
>customers should be able to take advantage of that capability at
Again -- I'll bet the product your company builds will likely cost
in the low 5 figures minimum -- especially if the port count approaches
more than 75 ports. Is that considered least cost? I'm not sure either --
but I'm leaning towards that not being too cost effective; plus with the
additional cost of out of band management (cause it cannot be in-band)
and the limited amount of rack space.....
>> So your argument that the IEEE should (basically)
>> adopt what
>> doesn't impact the existing installed base is a
>> justification, IMO. And as far as cost of
>> concerned --
>> this one cost customers a lot. Now -- I'm personally
>> the IEEE did do
>> this work, there are great benefits to it.
>Pardon my foolish concern for my customers, I guess we will
>have to disagree about their best interests. I recommend that
>have a nice cup of tea and relax. We can debate this matter
>to the point of calling each other foolish or
Dan, perhaps I shouldn't have stated it in that way. I should have
only implied it
>> Back to this topic, what will be engineered is power
>> existing Ethernet
>> Switching Chassis with new modules purchased by that
>I have no dispute with those who wish to offer that as a
solution. I am
>arguing that we should not impair the data pairs for 10/100T or
>customers to toss out their very efficient and cost-effective
>switches. Standards should be designed to provide flexibility
>> I haven't done the numbers -- but for those that have
>> small fixed Ethernet
>> Switch in a closet (<50 ports) -- I'd be surprised
if building a cost
>> effective external 'mid-span' power insertion device
>> those installations
>> were the norm, not the exception. Companies will
>> 'stackable' or
>> 'fixed' or 'non-modular' chassis that will supply DTE
>> If you don't
>> believe that's true -- wait and see. I'll bet there
will be many many
>> offerings by many vendors by the time this 'Standard'
>If you wish to perform the numbers regarding the justification
>for mid-span versus switch-based power insertion, I would be
>very happy to review and comment on your presentation.
That's competitive info and you know if -- so I'll pass.
>> >> Whether we choose the data pair or
>> >> spare pair should be conditioned more
on 1) the total cost
>> >> to the buyer of
>> >> equipment designed with DTE power in
>> >As a standards committee member, I would put
"must support the
>> >installed base of equipment without
interference" as a higher
>> >priority than cost. The cost of ripping out
existing gear is
>> >substantial. But what I have to say is less
relevant than the
>> >decision by the committee to require
compatibility with 10/100T.
>> Again, explain 802.1p/q mentioned above
>But it does not apply in this case because there is a very large
>base of VoIP product in the market.
>> >> 2) on the
>> >> needs of 1G and
>> >> faster links, than on the cost of
>> >Again, the committee has clearly expressed that
10/100T is a
>> >higher priority than 1000T. Unlike 10/100T, the
>> >today actually operates very robustly. Much of
>> >installed base has been built with
>> >but customers want to use it. If you have a PC
with an older 100T
>> >NIC installed, do you want its performance to be
impacted by the
>> >addition of mid-span patch panels that are
designed to inject
>> >power on PDTEs?
>> I guess I don't understand why a PC would be
connected to a Mid-Span
>> powering device and expecting power --- wouldn't that
>> blow-up that older
>> NIC? I sure think that NIC couldn't handle -48Vdc on
>> pair.... but I
>> could be wrong.
>That older NIC would likely fail the "assert power"
test, and would
>therefore not have power asserted, but might not operate
reliably due to
>Return Loss and Insertion Loss impacts on the data pairs if they
>to insert power. If you wish to understand this point more
>recommend that you review the numerous presentations already
given to the
>committee. They clearly explain it.
>> In the case of the "spare pairs" no
>> >exist. Sure, future 1000T products would have to
deal with power
>> >injection on their outside pairs, but 1000T is
>> >to do so with echo cancellers, FEC, and DSP
>> >> (Note that this
>> >> argument says that the woes of
existing 4-wire installations
>> >> is relatively
>> >> unimportant.) In other words, I
think that powering 1G is
>> >> more important
>> >> in the long term than cheaply adding
on to 10M ports'
>> >Unfortunately, that is not the direction that the
>> >already committed to. Support for 1000T should
not be demanded at
>> >the expense of either reliable or inexpensive
>> >> -- Norm
>> >Best Regards,
>> >Dan Dove
>> >HP ProCurve Networks
>> "At the end of the day... the most committed
>> James M. Polk
>> Sr. Product Manager, Multiservice Architecture and
>> Enterprise Voice Business Unit
>> Cisco Systems
>> Dallas, Texas
>> w) 972.813.5208
>> f) 972.813.5280
>HP ProCurve Networks
James M. Polk
"At the end of the day... the most committed win!"
Sr. Product Manager, Multiservice Architecture and Standards
Enterprise Voice Business Unit