Century Link provide a Calix 716GE-I ONT to their consumer gigabit (GPON) customers. This device has a weird 9-pin DIN connector providing standard 12V 2A power. The extra pins are likely used for communication between an external UPS and the ONT, so the device can take actions when the power drops (e.g. prioritize telephone traffic over internet traffic). However we don’t have or want a dedicated UPS for the ONT. We wanted to provide power over the existing ethernet connection.