Re: [802.3_B400G] [802.3_B400G_178B] Annex 178B Direction and the Scope of IEEE P802.3dj
All,
While the matter below started in the IEEE 802.3 Annex 178B Ad hoc meeting
last week, it is becoming an issue that will require Task Force discussion
and consideration. This matter will be discussed at next week's Annex 178B
Ad hoc meeting. I encourage task force participants to attend, and have
forwarded the meeting invite to the Task Force reflector.
Given that the ad hoc only received one other presentation, I would like to
use this time to discuss the matter in detail. Please attend if you can.
Regards,
John D'Ambrosia
Chair, IEEE P802.3dj Task Force
-----Original Message-----
From: Law, David <0000363ca596b6f2-dmarc-request@xxxxxxxxxxxxxxxxx>
Sent: Wednesday, September 3, 2025 8:19 AM
To: STDS-802-3-B400G@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_B400G] [802.3_B400G_178B] Annex 178B Direction and the
Scope of IEEE P802.3dj
Hi John,
I will summarise the scope of the IEEE P802.3dj PAR as defining physical
layer specifications of 200 Gb/s, 400 Gb/s, 800 Gb/s, and 1.6 Tb/s,
utilising >= 200 Gb/s signalling over copper and single-mode fibre PMDs. As
you are aware from our previous discussions regarding PAR scope, I aim to
interpret the scope statement in the broadest possible manner.
Since defining physical layer specifications includes defining their
sublayer interfaces, and since the PAR is silent on this subject, I believe
it is within the scope of the project to define physical layer
specifications using either existing physical layer interfaces (e.g.,
800GMII and 800GAUI-8), or using new physical layer interfaces defined as
part of the project (e.g., 1.6TMII and 800GAUI-4). I also believe that
defining new features (e.g., path startup function) for the new physical
layer interfaces that do not exist for the existing equivalent physical
layer interfaces is also within the scope.
Additionally, I believe that necessary modifications to existing physical
layer interfaces to support the new physical layer specifications are within
scope. However, I don't see anything in the PAR scope beyond defining new
physical layer specifications using the specific PMDs. As a result, I don't
believe that the PAR scope supports modifying existing physical layer
interfaces for anything beyond what is necessary to support the new physical
layer specifications. I, therefore, don't believe that it is within the
scope of the PAR to modify existing physical layer interfaces to add new
features.
Finally, since the scope includes '... utilising >= 200 Gb/s signalling over
copper and single-mode fibre PMDs', I do not believe it is within the PAR's
scope to define physical layer specifications that are not based on copper
or single-mode fibre PMDs using ? 200 Gb/s signalling.
Best regards,
David
-----
From: John D'Ambrosia <jdambrosia@xxxxxxxxx>
Sent: 29 August 2025 18:45
To: STDS-802-3-B400G-178B@xxxxxxxxxxxxxxxxx
Subject: [802.3_B400G_178B] Annex 178B Direction and the Scope of IEEE
P802.3dj
All,
Given the WG Recirculation Ballot currently underway, I have spent time
pondering the presentation & discussion in the Annex 178B ad hoc this week.
One of the observations noted in the presentation was:
AUI components is made up of xAUI-n's (constrained by xAUI-n
definition) & PMDs (no constraints)
In combination with an output of the ad hoc discussion:
x-AUI-n needs clarification to be more inclusive of other AUIs (i.e.
other than those defined in 802.3dj)
The group essentially noted it wanted to define this annex to be generic in
terms of PMDs and AUIs.
As I noted at the end of the presentation -
Solution needs to be considered for project scope.
Per the PAR
(https://urldefense.com/v3/__https://www.ieee802.org/3/dj/projdoc/P802d3dj_P
AR.pdf__;!!NpxR!hGWXDqh0bevhlkdLbKSFeJRP2W1zp25CgLiTObQLkZPB7-dyBk3ffcOSFqkT
AYfvTixp4RCOVUMzKg$)
5.2.b Scope of the project:
Define Ethernet MAC parameters for 1.6 Tb/s. Define physical layer
specifications, and management parameters for the transfer of Ethernet
format frames at 800 Gb/s and 1.6 Tb/s over copper and single-mode fiber
physical medium dependent (PMD) sublayers based on 200 Gb/ s or greater per
lane signaling technologies.
Using these new definitions for 800 Gb/s and 1.6 Tb/s, define physical layer
specifications and management parameters for the transfer of Ethernet format
frames at 200 Gb/s and 400 Gb/s, when applicable.
The first paragraph clearly limits the PMDs that can be addressed to those
PMD sublayers based on 200 Gb/s or greater per lane signaling technologies.
So it would seem to me that this annex needs to be constrained to PMDs that
utilize >= 200 Gb/s signaling:
For 200GbE: 200GBASE-CR1, 200GBASE-KR1, 200GBASE-DR1;200GBASE-DR-1-2;
For 400GbE: 400GBASE-CR2, 400GBASE-KR2, 400GBASE-DR2;400GBASE-DR-2-2
For 800GbE: 800GBASE-CR4;800GBASE-KR4; 800GBASE-DR4;800GBASE-DR4-2;
800GBASE-FR4;
800GBASE-FR4-500;800GBASE-LR4;800GBASE-LR1;800GBASE-ER1;800GBASE-ER1-20
For 1.6TbE: 1.6TBASE-CR8; 1.6TBASE-KR8;1.6TBASE-DR8;1.6TBASE-DR8-2
Additionally, this part of the scope statement needs to be considered:
Define physical layer specifications, and management parameters for the
transfer of Ethernet format frames at 800 Gb/s and 1.6 Tb/s over
Physical layer specifications defined in this project have focused on 200
Gb/s signaling for the AUIs for 200GbE, 400GbE, 800GbE, and 1.6 TbE and 100
Gb/s signaling for 1.6 TbE. Therefore 25 Gb/s and 50 Gb/s based AUIs (which
was not used to define physical layer specifications for 800GbE or 1.6 TbE)
for 200 GbE and 400 GbE do not appear to be in scope.
Additionally, while we defined 100 Gb/s signaling for 1.6TbE, the 100Gb/s
based AUIs for 200GbE, 400GbE, and 800GbE are already defined, and the scope
does not state "modify existing physical layer specifications."
Furthermore, the objective for 100 Gb/s based 1.6 TbE AUI was adopted to
support test equipment, which IMO doesn't seem to need "ILT." Do we really
need to devote our limited resources to it? I am struggling to believe this
should be a priority.
Furthermore, if we include other PMDs and AUIs, the TF, to do its job
properly, needs to consider them, otherwise how can we be assured they
actually work - and this raises an issue for me as Chair, hearing
presentations that are clearly out of scope.
This is a discussion that needs to be had with the WG Chair, David Law.
David - if you are reading this email, it would be appreciated if you can
reply to this email.
So, IMO, Annex 178B should address:
PMDs that utilize >= 200 Gb/s signaling:
For 200GbE: 200GBASE-CR1, 200GBASE-KR1, 200GBASE-DR1;200GBASE-DR-1-2;
For 400GbE: 400GBASE-CR2, 400GBASE-KR2, 400GBASE-DR2;400GBASE-DR-2-2
For 800GbE: 800GBASE-CR4;800GBASE-KR4; 800GBASE-DR4;800GBASE-DR4-2;
800GBASE-FR4;
800GBASE-FR4-500;800GBASE-LR4;800GBASE-LR1;800GBASE-ER1;800GBASE-ER1-20
For 1.6TbE: 1.6TBASE-CR8; 1.6TBASE-KR8;1.6TBASE-DR8;1.6TBASE-DR8-2
C2C and C2M AUIs based on 200 Gb/s
200GAUI-1, 400GAUI-2, 800GAUI-4, 1.6TAUI-8.
Full disclosure - I will be submitting comments based on this thought
process.
Regards,
John D'Ambrosia
Chair, Annex 178B Ad hoc
Chair, IEEE P802.3dj Task Force
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