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Re: Optical Connectors


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.

  • ANSI/TIA/EIA-568-B3 Optical Fiber Cabling Components Standard

        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.



----- 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 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.
** 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