Great article. Bravo! The principals, however, have only begun to describe the extent of disruption that will undoubtedly result from neutralizing the LAN/MAN diameter through the transparency of glass, but it's a great start, nonetheless, to reviving discussion about a technology whose time is long overdue.

Given my druthers, I'd have liked reading more about physical media issues that are almost certain to arise during every customer evaluation, given the absence of single-mode fiber (SMF) at the LAN level, since multi-mode (MMF) has heretofore been specified almost exclusively in those rare situations where enterprise fiber-based LANs in ordinary workplaces have been installed, at all.

And while it's true that MMF could be used in lieu of SMF in satisfying PON requirements, that would be very much like volunteering to the same distance limitations imposed by Category x cabling, only a couple of hundred meters longer.

PoE, too, in my opinion could stand more discussion, since the technique has become the tail that wags the dog, in some respects, and it will not be overcome easily unless it is addressed properly with solutions that can solve a range of terminal device power requirement contingencies. There are several alternative- and emerging- methods at this time that can be used for delivering low-voltage d.c. to desktops and APs that don't entail massive investments in GbE switches and the copper cages they sit in, and in some cases the PoE requirement could be obviated entirely without incurring operational or safety penalties.

I should note that this issue has been near and dear to me for over twenty years now, first having been involved with PONs during the mid-Eighties when passive splitters from Codenoll and CanSTAR, and Ethernet electronics from primarily Ungermann-Bass and 3Comm, were used. I recently posted a message to the CR-4 Forum (URL: http://tinyurl.com/6y49zu ) that some readers here may find of interest, since I covered many of the same issues as the reference article above, and then some. Enjoy!

frank@fttx.org