Patton
CopperLink 1214
The CopperLink 1214 from Patton operates over copper twisted-pair, coaxial or CAT-5+ cabling, eliminating the cost and delay of replacing installed cabling when inter-connecting IP-enabled devices. A built-in four-port Ethernet switch aggregates IP traffic from four sources for transmission over a single Ethernet connection. Those sources are: light/motion sensors, video cameras, entry-card readers, and personal computers.
http://www.patton.com/ethernet-extender/cl1214/