Patent attributes
A communications network tap, comprises a first terminal and a second terminal adapted to couple the tap in-line in the network and communicate data packets with network devices. A heartbeat generator is configured to generate a heartbeat signal, and a heartbeat insert circuit coupled to the first terminal and the heartbeat generator and configured to insert the heartbeat signal into data packets. A third terminal is coupled to the heartbeat insert circuit and adapted to couple the tap to a network monitor and communicate data packets with network monitor. A heartbeat remove circuit is coupled to the third terminal and configured to receive data packets from a network monitor and remove the heartbeat signal from the data packets. A heartbeat detector coupled to the heartbeat remove circuit and configured to detect whether the data packets include the heartbeat signal, and if not, to generate an alarm signal. A switch is coupled to the second terminal and configured to transmit data packets onto the network. Advantages of the invention include ensuring the integrity of network monitoring equipment.