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Thank you for summarizing all the discussions and please see my response below.
Chris Cole wrote:
Page 307 Table 88-1 states CAUI is optional for 100GBase-LR4/ER4. CL83A provides PMA to PMA CAUI electrical specifications which satisfy this optional
interface requirements for 100Gbase-LR4/ER4.
CL85 defines common pin out for the CR4/CR10 as well as SR4/SR10 and SFF-8436 defines the QSFP module. SR4/SR10 due to similarity is adopting
many aspect of SFP+ compliance boards. If SFF-8431 had not fully defined the PPI and compliance baords, I highly doubt 802.3ba would have define
the module interface due to the amount of time it would have taken. IEEE 802.3ba has ZERO information how CAUI will be used to implement a
100GBase-LR4/ER4 module, but I can see the following implementations:
o. Build the optics on the line card with CAUI - current specifications satisfy this requirement
o. Provide pluggable module with 5" host PCB and 5" of module PCB
o. Provide pluggable module with shorter host PCB and longer of module PCB
o. Provide pluggable module with longer host PCB and shorter of module PC
Based on just assumptions we can not write additional 4 set of specifications for CL83A!
If another body has solid information on the 100GBase-LR4/ER4 module definition then they can do much better job of defining module test points.
IEEE CL38 only defined jitter value and fortunately not th electrical level, if they would have then we would still had to support 2.4 V swing PECL with
termination resistors! I would even argue adding PPI definition in CL86 is questionable and we had long debate about in Portland. MSA and SFF
specifications with technology evolution can easily be updated but not the IEEE specifications.
If the requirements were known.
I just can't see how we can make such a growth assumption, what about if it is really bad proposal because or something not possible to meet,
because we did not have the facts!
How about crosstalk limits as defined in SFF-8083?
Are you telling me the host PCB and the module PCB can be any length with same set of compliance points?
Adding additional 4 compliance points to CL83A could delay the project! Chris you are absolutely right that we have not seen any useful presentation on 100Gbase-LR4/ER4
module implementation or a clear request, but I did find your presentation http://www.ieee802.org/3/ba/public/may08/cole_02_0508.pdf page 5 showing a transceiver architecture
from 40000 ft. Searching on Google did not turn anything useful either and as far as I know 802.3ba has not received any liaison report or requests from any MSA or SFF group
that might be working on a 100G module, John should be able to confirm this.
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