Pluggable communication modules, e. Alarm verification includes capturing by an image capture device at least one image in response to a detection event, and transmitting a first data signal including the image to a local signal processing device. Whenever the sense voltage exceeds a threshold, output power of the power supply is limited by increasing the sensed magnitude of each occurrence of the flowing currents by adding to each sensed magnitude a voltage proportional to the sense voltage. A third connection for a third conductor in the transmission line can be connected via the series circuit formed by a switch and a first diode to the positive output of the rectifier, and via the series circuit formed by the switch and a second diode to the negative output of the rectifier. The processes include those for replicating and caching frequently-accessed content, and multicasting content customized per region or locality.