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Re: [STDS-802-3-400G] New 50G/100G/200G SG - Potential Impact on 802.3bs?

It won’t be a slam-dunk to create a CAUI-2 using KR-FEC when the CDAUI-8 is using KP-FEC.  Also if we are considering 100GBASE-DR or 100GBASE-LR2 those are likely to want the KP-FEC.     I expect also that the 50G serial backplane and copper links are going to want the KP4  FEC.   Ie the KP-FEC will be in any chips designed for 50G PAM4. 

 

Mike Dudek 

QLogic Corporation

Director Signal Integrity

26650 Aliso Viejo Parkway

Aliso Viejo  CA 92656

949 389 6269 - office.

Mike.Dudek@xxxxxxxxxx

 

 

From: John D'Ambrosia [mailto:jdambrosia@xxxxxxxxx]
Sent: Thursday, December 03, 2015 12:00 PM
To: STDS-802-3-400G@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-3-400G] New 50G/100G/200G SG - Potential Impact on 802.3bs?

 

Jeff,

If I get your point here – the only thing you are adding to what I already pointed out was the interaction between a x2 C2C with a x4 C2M.

 

Right?

 

John

 

From: Jeffery Maki [mailto:jmaki@xxxxxxxxxxx]
Sent: Thursday, December 3, 2015 2:37 PM
To: STDS-802-3-400G@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-3-400G] New 50G/100G/200G SG - Potential Impact on 802.3bs?

 

I support what Chris is saying. In addition, I think we will need to examine support of existing 100G PMDs with a new optional electrical interface, the CAUI-2 (2x50G) C2M. Further, we should examine CAUI-2 C2C, where the C2M interface is CAUI-4. The desire for things to persist to work with KR4 FEC rather than requiring a new FEC code shall be high.

 

Jeff

 

 

From: Chris Cole [mailto:chris.cole@xxxxxxxxxxx]
Sent: Thursday, December 03, 2015 8:53 AM
To: STDS-802-3-400G@xxxxxxxxxxxxxxxxx
Subject: Re: [STDS-802-3-400G] New 50G/100G/200G SG - Potential Impact on 802.3bs?

 

The idea of rolling 200G into the 400G project is compelling. In prior discussions, we had rejected this as too late for 802.3bs TF, so it’s encouraging to see we are willing to revisit. One mental test of why this makes sense is to consider what we would have done in 400G Study Group if we knew what we know now. Given the CFI support, it could be argued that most people would have supported both 200G and 400G. If anything, 200G is more compelling.


However, the inclusion of 100G in the 400G project is much less clear. Several arguments can be made that it more naturally belongs in the 50G project. An important consideration is that for both 50G and 100G, backwards compatibility with existing 25G I/O interfaces is important. Specifically we will want 50G supported with 2x25G electrical I/O and 100G to be supported with 4x25G I/O (CAUI-4). This suggests that for 50G single wavelength and 100G WDM2 solutions, KR4 is the appropriate FEC. For both, this gives reasonable optical margin with PAM4 modulation. On the other hand, for 200G WDM4 KP4 is a better choice, same as for 400G WDM8.


Adding only 200G to the 400G project makes for much cleaner documentation modification. Broad market potential for 200G is the same as for 400G. We don’t need to introduce new justification which is required for 100G. Not having 100G, removes any dependence on any other project, so there is no need to discuss this.

 

Chris

 

From: John D'Ambrosia [mailto:jdambrosia@xxxxxxxxx]
Sent: Thursday, December 03, 2015 6:00 AM
To: STDS-802-3-400G@xxxxxxxxxxxxxxxxx
Subject: [STDS-802-3-400G] New 50G/100G/200G SG - Potential Impact on 802.3bs?

 

Dear Task Force Participants,

This email is to make sure that everyone is aware of conversations happening in the 50/100/200G Study Group Phone Conference that happened yesterday – Dec 2.  There has been discussion at how the multi-lane 100G/200G solutions might be rolled into the 802.3bs project.  To that end – I gave a presentation at the conference call that looked at potential modifications / additions to our PAR / CSD.  See http://www.ieee802.org/3/50G/public/adhoc/archive/dambrosia_120215_50GE_NGOATH_adhoc_v2.pdf

 

I encourage everyone to review this presentation and consider the findings on the last few pages.  Individuals may wish to participate in the upcoming 50/100/200G ad hoc calls that Mr. Nowell has planned.  For more information see http://www.ieee802.org/3/50G/public/adhoc/index.html.

 

I will be working on the meeting announcement for the January interim, and anticipate that there will be a joint session of our Task Force with the Study Groups to further consider these implications.

 

Regards,

 

John D’Ambrosia

Chair, IEEE P802.3bs 400GbE Task Force