RE: Signal vs. Idle debate (A picture is worth a thousand words)
Ralph , et. al.
I am simply going to add a comment into a portion of this exchange. I
have no intention of either fanning the existing flame war nor starting
another one. Please read my comment in that vein.
Comment in line below.
Bob Bell
At 17:20 5/8/2000, Ralph.Andersson@xxxxxxxxxxx wrote:
Mr Polk,
>Ralph
>At 04:21 PM 5/5/2000 -0700, Ralph.Andersson@xxxxxxxxxxx wrote:
>>Phantom power via the signal pair requires the addition of an
additional
>>transformer in the signal path; the effect on the return loss is
unknown and
is
>>may be detrimental.
>So... and in your words BTW, the phrase "... the
>effect on the return loss is unknown and is may be detrimental."
means ...
This comment is two-fold:
First, to date, there has been no presentation on the effects on return
loss
when an additional transformer is added to the data link. Look for
this to
change at the Ottawa Interim. My company, TDK Semiconductor, voted
against the
motion to use the idle pair at the March Plenary. We thought the
vote premature
as the data was not present to support such a vote. We at TDK are
maintaining
an open mind. ...
>>> I guess the thing that I am concerned about is that the
committee appears to be ready to make a decision as to the best solution
for powering via the MDI without getting the necessary data to determine
if there is another answer which would meet a larger user community. I
also voted against the use of the idle pairs because the engineering data
to prove or disprove its usability had not at that time been gathered and
so was not available to us. My question is do we just assume that the
method is guilty until proven innocent and thus force ourselves to move
to the idle pairs by default, or do we as a committee attempt to provide
the time to research the question and then make the decision based on all
the information. If there is such an overriding need for speed that the
time for engineering design is not available, then maybe it should be so
stated in the objectives. I for one feel that we should do it right
rather than the expediently. This is my personal feeling and is
independent of the perceived position of my company. I am personally NOT
trying to delay the decision of the group in favor of a De Facto
standard. I agree with Geoff that there is a real need for industry
concensus standards. However, to simply rush into a standard without
providing all concerned with the opportunity to provide valid input seems
to me to be doing less that our best for the industry. At least that is
how I see it.
<<< Bob Bell
...<snip>...
Bob Bell
Cisco Systems Inc.
801-294-3034(v)
801-294-3023(f)