Zoom CableModem - Manual (Page 10)

6 Zoom USB Cable Modem User’s Manual
The diagram below shows a typical cable modem installation. The
cable modem should be placed on a port of the first splitter inside
your home or office, and should be kept on a separate circuit from
your cable television service.
It is possible that the signal coming from the cable modem back to
the cable provider’s central office may interfere with signals from
the TV set-top box for Pay Per View or Video on Demand
services. If this happens, install a high-pass filter at the input of the
2:1 splitter going to the TV sets (see the preceding diagram).