Re: [802.3_100GCU] Successful May Interim
Ali,
I agree that construction and wrap are important. The difference is that AWG is more easily understood than construction and wrap, and it seemed to be used as a general rule of thumb in gauging the characteristics.
The advantage of using TIA and IEC specifications is that they do specify bend radius. From Mark Gustlin's presentation and from general feedback from the industry, there seemed to be concern with the bend radius of twinax. Mark let me know that he felt the 24 AWG twinax should be able to meet the bend radius requirements.
I was merely trying to help the study group make a stronger case for broad market potential by creating a target for bend radius via the AWG. I thought it would be a very simple addition considering it seemed to be the assumption most people were using. I was wrong. The feedback has been very strongly opposed to mentioning AWG or bend radius as part of the project's objectives. I guess I can only hope that TF members will presented with both mechanical and electrical specifications so they can make the best decision to satisfy the market.
Thanks,
Brad
On Tue, May 31, 2011 at 4:06 PM, Ali Ghiasi
<aghiasi@xxxxxxxxxxxx> wrote:
Brad
UTP/Optical fibers are typically standardized by TIA/IEC then in IEEE we include the cable reference in our reach objective.
In the case of copper cabling I am not aware of specific standard that define the AWG, construction, or the type of wrap.
It would be incomplete if we just reference AWG of cable, since construction and wrap are as important.
Thanks,
Ali
On May 31, 2011, at 11:59 AM, Brad Booth wrote:
Chris,
My concern is about the objective. There is no mention of AWG in the twinax reach objective, even though it is probably fair to assume most people based their decision on 24 AWG.
Study groups have usually spent time trying to be specific when it comes to the UTP and optical cabling in reference to the reach. In this case, it may be useful to state that the 5m reach is based upon 24 AWG, because while the industry complains about its bend radius, it may be deemed acceptable for that reach. If the TF was to adjust the reach based upon using 24 AWG or decrease the gauge, then different criteria come into play and comments/ballots can be submitted accordingly.
It has been stated repeatedly in previous SG meetings is that the objectives are a contract with the WG about the work to be performed by the TF. It may be in the SG's and WG's best interest to ensure that there is good agreement on the gauge being assumed for a 5m twinax reach.
Cheers,
Brad
On Tue, May 31, 2011 at 10:10 AM, <CDimi80749@xxxxxxx<mailto:CDimi80749@xxxxxxx>> wrote:
Brad,
Please find responses inline....
Brad: If there is no information provided that indicates 24 AWG twinax copper cabling can meet the bend radius, diameter and weight requirements for inter-rack and intra-rack interconnect, then has the study group sufficiently responded to broad market potential?
Chris:
>>24 AWG twinaxial copper cables are used for inter-rack and intra-rack interconnects.
>>Although there are documents that address specifications for 24 AWG twinax copper interconnects related to bend radius, they don't constitute requirements for inter-rack and intra-rack interconnect applications.
>>For CX4, CR4 and CR10 the cable assembly differential characteristics are specified. During the development of these specifications, 24 AWG cable assembly measurements were presented.
>>In the formulation of the IEEE 802.3 100 Gb/s Backplane and Copper Study Group call for interest material, I provided outer dimensions for 24 AWG twinaxial cable - 9.3 mm (0.366).
Regards, Chris
In a message dated 5/30/2011 10:50:28 P.M. Eastern Daylight Time, bjbooth@xxxxxxxxx<mailto:bjbooth@xxxxxxxxx> writes:
John,
Glad to hear that the meeting was successful.
Was there any consideration for listing the gauge of the wire for the 5m twinax copper cabling objective?
At the meeting in Singapore, there was a request during the straw poll to list the gauge of wiring and it did slightly alter the results of the poll. Even the presentation by Mark Gustlin at last week's meeting highlighted the importance of bend radius and diameter which can be directly related to the gauge of wire. Did the study group discuss the bend radius and diameter requirements? Is it fair to assume that the gauge of wire for the twinax copper cabling objective is the same used in the Singapore straw poll (24 AWG)? If 24 AWG is assumed, was there any information presented or provided to indicate that the cable would be able to meet the bend radius, diameter and weight requirements for the intended application?
If there is no information provided that indicates 24 AWG twinax copper cabling can meet the bend radius, diameter and weight requirements for inter-rack and intra-rack interconnect, then has the study group sufficiently responded to broad market potential?
Thanks,
Brad
On Sat, May 28, 2011 at 11:39 PM, John D'Ambrosia <jdambrosia@xxxxxxxxxxxxxxx<mailto:jdambrosia@xxxxxxxxxxxxxxx>> wrote:
Dear Study Group Participants,
I hope everyone had safe journeys home. I have to say it was one of my more adventurous travels. However, given the success of the meeting, the travel was well worth it!
The Study Group was successful in reaching consensus on the objectives, PAR, and 5 Criteria responses. They have been posted, and may be found at http://www.ieee802.org/3/100GCU/index.html.
July will be the next key milestone, as we look forward to the necessary approvals to move from Study Group to Task Force.
The minutes will be posted shortly.
Best Regards,
John D’Ambrosia
Chair, IEEE 802.3 100Gb/s Backplane and Study Group