The VSC7140 is a dual Fibre Channel repeater which can be used in Hubs, JBODs or any Fibre Channel Subsystem requiring clean incoming and outgoing signals at a bulkhead connector. The digital Clock Recovery Unit (CRU) recovers incoming data from an external device, amplifies it and attenuates jitter. A digital Signal Detect Unit (SDU) determines whether the incoming signal contains invalid Fibre Channel data. A 2:1 multiplexer forms a Port Bypass Circuit (PBC) to route either recovered incoming data or SI to SO. Fibre Channel subsystems requiring signal cleanup at the bulkhead would connect RX1 to the incoming signal and SO1 to the internal subsystem's input. RX2 would connect to the output of the subsystem and SO2 would connect to the bulkhead. For Hub applications, SI would connect to the previous Hub Node and output data to the external device on TX. Incoming data from the external device on RX is recovered and cleaned up and passed to the next Hub node on SO. If the external device is not functional, SI is passed to SO.