said by K3SGM:The original manufacturer, American Fiber Concepts, as known as AFC, produced the original 610x SFH ONT.
They were later acquired by Tellabs. Which along with Motorola make the current models in use.
The 610, and even 611's would fail due to video problems.
The current 612's use a different Power Supply, and BBU, and are supposed to be free of the prior problems.
The 611 and 612 look almost identical, with the exception that the 611 supports 4 Pots ports, and the 612 only 2.
The 612 is the first MoCA enabled unit, which runs everything off of the coax, and eliminates the need for CAT5 wiring between the ONT and router.
All 3 units utilize a completely different PS and BBU, so the re-install can be quite lengthy in some cases.
AFC = Advanced Fiber Communications. The original 610 and 610x used a different APSU/BBU than the 611/611i/612, since the older ONT's were manufactured by AFC. Tellabs completely redesigned the 1600-series ONT's after AFC was purchased. The newer APSU/BBU can be used with the older 611i/612, so it depends on which ONT is currently in place when an ONT replacement is required.