As a followup to a discussion we had after the WLUG meeting, here are some good pages to read about how FiOS works. Verizon is using Passive Optical Networking, either BPON or GPON depending on the CO. The downstream side is shared, since by its very nature a PON's downstream direction is broadcast on a single wavelength--the light goes from the OLT to every customer's ONT on the PON "tree". For privacy each customer's downstream traffic is "encrypted" so only the intended ONT/customer can decrypt it. The upstream side is shared via TDMA since only one customer's ONT can trasmit at a time on the single upstream wavelength "up the tree" towards to root of the PON where the OLT lives...each ONT gets a "time slot" for upstream transmissions. There can be up to 32-128 customers shared on a single PON. http://www.dslreports.com/faq/verizonfios http://en.wikipedia.org/wiki/Optical_Line_Termination