| Thread Links | Date Links | ||||
|---|---|---|---|---|---|
| Thread Prev | Thread Next | Thread Index | Date Prev | Date Next | Date Index |
Hi Vineet,
I think it makes a lot of sense to retain the 802.3bj host loss. The case in point would be a switch with 4x25G connectors that may be used for either a signal 100G Ethernet port (100GBASE-CR4 per 802.3bj) or four 25G Ethernet ports (25GBASE-CR per new 25G project).
From: Vineet Salunke (vineets) [mailto:vineets@xxxxxxxxx]
Chris,
We heard on the call yesterday, at least 3 demands that do not exactly match Clause 92. · Need to reduce the host loss on the server side, to reduce total loss and avoid use of FEC. · Need to further optimize around 3m cables for above. · And I also heard need to allow larger host loss for the TOR switch side (when using RS-FEC).
So can we avoid the direct reference to Clause 92 specifications ?
--vineet
From: Christopher T. Diminico [mailto:00000025925d7602-dmarc-request@xxxxxxxx]
Rich,
Hopefully this addresses both you and George.
Given the intent is to operate over channels consistent with the channel (TP0-TP5) specified in IEEEStd802.3bj-2014 Clause92.
•Define a single-lane 25Gb/s PHY for operation over channels consistent with the channel specified in IEEEStd802.3bj-2014 Clause92 (Fig 92-2 - TP0-TP5) Regards, Chris DiMinico
-----Original Message----- Both suggestions allude to a specific host/module budget which I believe needs to re-evaluated in task force. Perhaps:
Define a single-lane 25Gb/s PHY for operation over copper twin-axial cables, host channels, and module channels consistent with channels (TP0-TP5) specified in IEEEStd802.3bj-2014 Clause93
This sort of reinforces a single silicon solution.
From: George Zimmerman [mailto:george@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx]
Chris – Clause 92 has a lot of non-channel stuff in it, and the parenthetical insert, while clarifying to those who know clause 92 intimately, isn’t perhaps as clear as you could be. Pointing to the correct subclause, a figure or a table would be a lot better.
The wording itself leads to confusion because it says “over copper twinaxial cables consistent with”, but TP0 to TP5 includes more than the twinax cables, as you know. We end up with a couple of choices: 1) Just identify the cables in clause 92, or 2) Say operate over the whole TP0 to TP5 channel in clause 92 (I apologize because I have another call which conflicted with yesterday’s meeting – I don’t have an opinion on whether using the whole channel from TP0 to TP5 is in fact the correct objective, or whether you want to do just the cables) If you just want to do (1) just the cables, the cable assembly is specified in 92.10 (and references elsewhere), I would suggest stating •Define a single-lane 25Gb/s PHY for operation over copper twin-axial cables consistent with cable assemblies specified in IEEEStd802.3bj-2014 Clause92.10
And, if you want to do the whole channel, including the PCB, as you stated, from TP0 to TP5, Clause 92.9 clearly specifies this (by referencing other subclauses)
•Define a single-lane 25Gb/s PHY for operation over copper twin-axial cables consistent with cable assemblies specified in IEEEStd802.3bj-2014 Clause92.9
Note I’m looking at draft 3.2 of the 802.3bj, and don’t have the final published version.
George Zimmerman Principal, CME Consulting Experts in Advanced PHYsical Communications Technology 310-920-3860
(PLEASE NOTE NEW EMAIL ADDRESS. THE OTHER WILL STILL WORK, BUT PLEASE USE THIS FOR CME BUSINESS)
From: Christopher T. Diminico [mailto:00000025925d7602-dmarc-request@xxxxxxxx]
Colleagues,
Based on the discussions of the objective given on slide 9 second bullet in http://www.ieee802.org/3/25GSG/public/adhoc/architecture/nowell_081214_25GE_adhoc.pdf during the ad-hoc yesterday, I suggest we explicitly identify 802.3bj channel by adding (TP0-TP5).
Change from •Define a single-lane 25Gb/s PHY for operation over copper twin-axial cables consistent with channels specified in IEEEStd802.3bj-2014 Clause92 To •Define a single-lane 25Gb/s PHY for operation over copper twin-axial cables consistent with channels (TP0-TP5) specified in IEEEStd802.3bj-2014 Clause92
Regards,
Chris DiMinico
-----Original Message----- Sorry everyone – calendar screw up on my side around the re-arranged architecture ad-hoc meeting. Will update soon with improved logistics.
Mark
On 8/19/14, 5:42 PM, "Mark Nowell (mnowell)" <mnowell@xxxxxxxxx> wrote:
Dear 25Gb/s Ethernet Study Group Members,
A few reminders and updates:
1) Optical Ad-hoc is tomorrow Wed 8/20 @ 9am PST. Dial in details are here: http://www.ieee802.org/3/25GSG/public/adhoc/index.html
2) Architecture ad-hoc meeting next week has moved to Wed 8/27 @ (am PST (shifted from Tues). Dial in details are here: http://www.ieee802.org/3/25GSG/public/adhoc/index.html
3) Reminders on Call for presentations and September Meeting planning. Presentation request deadline is Friday Aug 29th. Please see my original email for details on meeting logistics and travel planning (We meet all-day Thurs and Friday). http://www.ieee802.org/3/25GSG/email/msg00004.html
As a reminder, the September Study Group meeting has limited meeting time and the presentations will be focused on the Study Group work of building objectives, developing responses to the CSD (5 Criteria) and PAR. Presentations outside of the scope of those priorities will be given time on agenda as possible.
Regards…Mark |