Re: Optical Connectors
As one member of the user community, I would like to go on the record
that some form of standardization in the connector interface would be
appreciated.
Although IEEE did not partake in the "connector wars", they have been
going on. At this point, there do appear to be some clear indications
of what the winners will be, and what some of the losers are.
I do not think that solely identifying the SC connector in the standard
is a good option. Most likely most of the interfaces sold will not use
the SC, they will use one of the SFF options.
If some limited number of connector options were detailed in the
standard, it would be of great benefit to the user community. At this
point I would vote for the inclusion of three standard interfaces (the
SC and two SFF versions). I think concensus could be reached in that
regard.
Gair
----Original Message----
David,
There is precedent for having two connector types in the standard (see
39.5.1 MDI = Style 1 (DB9) and Style 2 for GigE Cu)
I doubt that putting a large number of connector types in the standard
would be well received. But, two isn't exactly a large number.
I don't see why interoperability should not be a question for two
connector types any more than it would be for multiple port types; these
wouldn't
interoperate either.
It certainly seems like another option.
jonathan
-----Original Message-----
From: David Kabal [mailto:dkabal@xxxxxxxxxxxxxxxxxx]
Sent: Tuesday, July 18, 2000 3:02 PM
To: HSSG_reflector (E-mail)
Subject: RE: Optical Connectors
Jonathan:
As an open question, what is the impact of having more than one
optical connector specified in MDI of the 802.3 standard? Is this an
interoperability
question or can it be left flexible without adversely affecting the
standard. Is this similar to the Power over DTE decision to define two
different wiresets that
could be used to "transmit power", and every receiver had to accept
both, or is this a bogus analogy?
Throwing my personal opinion into this:
I can see near-term implementations in SC, moving to LC in the next
year, so I would prefer to have a standard that specified only LC, and I
would not be
adverse, if it were possible, to include both connectors as
"possible MDIs".
Cheers,
Dave
-----
David Kabal
Photonics Engineer, OPTera Metro Solutions, Nortel Networks
Phone: 613.270.5953 Fax: 613.591.2035
e-mail: dkabal@xxxxxxxxxxxxxxxxxx
-----Original Message-----
From: Jonathan Thatcher
[mailto:Jonathan.Thatcher@xxxxxxxxxxxxxxxxxxxx]
Sent: Tuesday, July 18, 2000 11:49 AM
To: HSSG_reflector (E-mail)
Subject: Optical Connectors
I have opened this thread to continue the discussion on
optical connectors. So far (what has come into my reader), we
have the following comments:
-----------------------
"Bill Wiedemann: Regarding 850CWDM we are planning to make
first implementations with duplex SC moving to LC
with small form factors. Our expectation is that small form
factor with LC could be available a year from today. "
-----------------------
"Jim Tatum: I would assume that 802.3ae would do the same as
802.3z, and NOT specify conectors. "
-----------------------
"Ed Chang: There are so many different form factors, and
connectors, which even the GbE and Fibre Channel market
can not get consensus."
-----------------------
If we review the 802.3 Ethernet specification, we see that we
have identified connectors for each variant (I don't
remember an exception). For example:
7.6.2 AUI Configuration cable
9.9.5.2 Optical for repeaters
...
38.11.3 MDI = Duplex SC for GigE Optics
39.5.1 MDI = Style 1 (DB9) and Style 2 for GigE Cu
While I remember no rules that require us to do so, it seems
obvious that there exists a precedent which should guide
our decision.
In 802.3z, we specifically took a vote to avoid connector
discussions ("connector wars")**. We could do the same in
802.3ae. If we did, I would argue that we would, effectively,
be retaining the duplex SC optical connector specified in
clause 38.
My PERSONAL preference would be to specify the LC connector.
Rationale:
1. There seems to be an overall inclination to move in that
direction.
2. It sets the stage for some kind of "Small Form Factor" 10
Gig transceiver.
3. I don't think that it would negatively impact the cost of
the transceiver in the 2002 (standard completion time frame).
As CHAIR, I don't want to use up any cycles on this. If there
isn't sufficient consensus to agree on an alternative to the
SC, we should just adopt the SC and move on.
jonathan
** In reality, this was bumped up to 802.3 because neither I
(sub-chair for PMD) nor Howard (802.3z chair) wanted to
use precious committee time for the discussion.
Jonathan Thatcher,
Chair, IEEE 802.3ae (10 Gigabit Ethernet)
Principal Engineer, World Wide Packets
PO BOX 141719, Suite B; 12720 E. Nora, Spokane, WA 99214
509-242-9000 X228; Fax 509-242-9001;
jonathan@xxxxxxxxxxxxxxxxxxxx
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