A network device within an outdoor broadband unit receives, via Ethernet over coaxial cable signals, Internet Protocol (IP) data traffic originating from a device within a local area network (LAN). The IP data traffic is buffered in a memory within the outdoor broadband unit. A forwarding plane module of the network device sends the IP data traffic toward a destination via an air interface for a wide area network (WAN). The network device receives, via different Ethernet over coaxial cable signals, IP control traffic originating from the device within the LAN. A control plane module of the network device implements the instructions in the IP control traffic to initiate a test function for the network device.