A:Answer If your system is wired with BNC cable (where you have a power cable and a video cable together), then no. Cat5 is Ethernet cabling not BNC cable.
If you are talking about an Ethernet wired system, then you should read the tech support info or contact someone at Night Owl on their chat lines and ask. If the system requires Cat6 cable, then I doubt Cat5 would work correctly -- but don't know for certain.