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Re: [802.3_100GNGOPTX] SMF and MMF Ad Hoc meetings: MMF objective



Hi Jeff et all

I assume ‘Lock-out’ isn’t addressed standards because it is an aspect of a particular business model.

If it  is universally a bitter experience, I wouldn’t expect a business model that includes it to be successful (e.g. people wouldn’t choose a host that uses lock out to constrain  what modules may be plugged into it).

 

On the plus side, lock-out could help ensure a degree of system level quality control, since a host card only uses modules that have been pre-determined to be fully operational with the host, not only electrically and optically, but with proprietary control and monitoring software.  A downside may be that generic modules can’t be used in a host with lock out.  Isn’t this  a bit like buying an Airbus, and only using Airbus approved components?

 

At present IEEE has PICS that describe compliance to the standards specifications, but aside from adding a PICS which says Caveat Emptor, I don’t see what can be done in a standards body.

Best wishes

jonathan

 

 

 

 

From: Jeffery Maki [mailto:jmaki@xxxxxxxxxxx]
Sent: Tuesday, February 28, 2012 9:55 AM
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_100GNGOPTX] SMF and MMF Ad Hoc meetings: MMF objective

 

All,

 

Lock out codes can be employed with even pluggable transceivers.  So, we would be defining a standard that would actually enable continued behavior that the end customer finds to be a “bitter” experience.  They would have to buy and stock two different system specific modules, a different one for each end.  It sounds to me like the real industry solution is to be found elsewhere.

 

Jeff

 

 

From: Kolesar, Paul [mailto:PKOLESAR@xxxxxxxxxxxxx]
Sent: Tuesday, February 28, 2012 6:20 AM
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_100GNGOPTX] SMF and MMF Ad Hoc meetings: MMF objective

 

Stephen,

Your points are well taken.  It’s not expected that an interoperable very short reach PMD standard would produce a solution as cheap as AOCs.  

 

But such a standard provides a potentially lower cost alternative to an SR4 with longer reach, depending on the technology boosts that are used, while solving a very real problem.  The trouble with AOCs is that if port-lock-out policies are in force, both ends of the channel must plug into the same brand of switch or server.  That is an unattractive constraint customers face with surprise at first followed by bitterness.  They fault IEEE for not doing its job to ensure interoperability.  A very short reach solution would remedy that by providing an interoperable alternative to AOCs.  The customer gets the best of both world:  AOCs when the brand is common at both ends, and a lower cost interoperable solution when they are not.

 

Regards,

Paul

 


From: Trowbridge, Stephen J (Steve) [mailto:steve.trowbridge@xxxxxxxxxxxxxxxxxx]
Sent: Tuesday, February 28, 2012 7:51 AM
To: STDS-802-3-100GNGOPTX@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_100GNGOPTX] SMF and MMF Ad Hoc meetings: MMF objective

 

Hi Brad,

 

> If there is market potential for an AOC to provide a short reach solution, then there is probably market potential for the study group to consider a short reach objective.

I’m not sure that necessarily follows. The bar is far lower to come up with an AOC, since the AOC vendor just needs to meet the CAUI spec at each end and what they do in the middle is their business (and may rely on whatever tricks and techniques that particular vendor is good at). Whether all vendors pick the same methods inside of the AOC is irrelevant.

The bar is much higher for a short reach objective: you would need to have confidence that you can make the same thing work based on a “least common denominator” of what the various suppliers can do and that you can write an interoperable spec around that that allows the two ends to come from different vendors, and that you have confidence you can get 75% to agree to do it the same way with an acceptable amount of debate to get there. It is not clear that you could ever make this solution as cheap as one where the same vendor has control of the entire link and can optimize the solution based on their own capabilities.

Regards,
Steve