Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

RE: Optical Connectors




I think the WAN versions of 10GBE introduce another
levelof complexity to connector considerations. Telcom
carriers, who will presumably be a major user of these
parts have numerous internally standardized connector
systems. This standardization is often for the entire
telephone system of a country and, in a few cases, is
even required by law. This is why the ITU doesn't
specify connectors in SONET standards.

I don't think we should get pulled down into the
connector quagmire. As Ethernet expands to touch other
pre-existing domains, the level of complexity /
confusion increases logrithmically. This is a case
where the market should decide.

Jay
--- Jonathan Thatcher
<Jonathan.Thatcher@xxxxxxxxxxxxxxxxxxxx> wrote:
> 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 
> 
>  
> 
> 


__________________________________________________
Do You Yahoo!?
Get Yahoo! Mail  Free email you can access from anywhere!
http://mail.yahoo.com/