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The question, ‘will a signal conditioner be always needed?’, I believe has been answered negatively. That’s clear to me both from the support I see for the baseline proposal and direct connection to the host IC as well as the shift from Xenpak to XFPs to SFP+. I don’t disagree that for those whose systems will always need signal conditioners, a more integrated solution will be beneficial.
From: Gary Nicholl
If it turns out that a signal conditioner will always be needed and a direct attach between the host IC and the pluggable module cannot be supported (at least for the many situations you mention below), then I think the signal conditioner should be integrated into the pluggable optical module (and ideally into the existing Tx and Rx ICs in the module as Ryan as suggested in the past).
This would provide the lowest overall system power (and especially if the SC is integrated into existing ICs in the module). It also means that we would have one less electrical interface to deal with, as the PMD service interface would now be an internal module interface completely under the control of the individual module vendors and there would be no need to specify it within 802.3ba (which would save us all alot of work).
Perhaps, I can point this out before Ryan. It seems to me that many pcb layouts will present sufficient challenges such that a direct connection between the host IC and pluggable module will not be supported and a signal conditioner will be needed between the host IC and module. This means that for reasons other than extending the optical link reach, the means to extend the optical link reach are in place at least for these situations. All that is needed then is a way to permit the installer to take advantage of the optical link extension that an external signal conditioner, adjacent to but not included in the module, provides. It will be frustrating to have all the pieces paid for and in place and not be able to take advantage of the extended link reach that they offer.
By the way, a similar situation exists with respect to using FEC.
Well, sadly that’s what has been happening in the 10G world, people are forced to amortize the cost of 300m reach (LRM), while in reality the number of people who need 300m is close to 0.
That’s why I am strongly in support of your approach of keeping the 100m objective as primary goal.
Frank, OM4 can add as much cost as it wants to, the beauty is the added cost goes directly where it’s needed, which is the longer links. Alternatives force higher cost/higher power consumption on all ports regardless of whether it’s needed there or not.
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From: Petar Pepeljugoski
From: Jeff Maki