One of the objectives of the 802.3ae is to "Support fiber media
selected from the second edition of ISO/IEC 11801 (802.3 to work with SC25/WG3
to develop appropriate specifications for any new fiber media)" as stated in the
HSSG Objectives Part 2 and as it was the case in the development of the
802.3z. Being a long time attendee and a US TAG F/O expert to the
SC25/WG3 I'd like to share with you the F/O connector status at the TO
(Telecommunication Outlet or simply Wall Plate where the equipment plugs
in) within various premises cabling standards.
- ISO/IEC WG3 11801 - International Premises Cabling
Standard
2-nd edition of the 11801
draft standard scheduled for completion first quarter of 2001 specifies at the
TO duplex SC only. It allows use of the SFF (Small Form
Factor) connectors
anywhere else for as long as: a) they are standardized by the IEC
86B and b) are of the RJ-45 outline at the TO.
- EN 50173 (2000): Information technology -
European Generic Cabling Systems Standard
Draft EN 50173 scheduled
for completion first half of 2001 follows the ISO/IEC 11801. Duplex SC at
the TO with SFF as alternate for high density application's.
Specifies duplex SC and
any of the SFF connector's documented by the TIA/EIA FOCIS (Fiber Optic
Connector Intermateability Standard)
Furthermore I'd like to make an observation that in case of
copper media we do have a present 17 different connector options including: UTP
(8 possible connectors based on the performance category 3,
5, 5e, 6 and physical wiring of T568A and T568B; ScTP (8 possible
connectors) and a Data Connector. Category seven
not counted yet but there are two to four more options at present. I don't
know how but it works.
Based on the above I do suggest to leave the connector
issue to the users.
Hope this
helps to further clarify our work focus.
Regards,
Tad
----- Original Message -----
Sent: Tuesday, July 18, 2000 10:48
AM
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