Patent ID: 7327672

Claim:
A data communication node, comprising: a plurality of channel devices, each comprising: an input port; an output port; a data receive port configured to receive a channel data signal; a data send port configured to provide a transmit data signal to a data communication channel; and a signal routing arrangement configured to route data from said input port to said output port or to said data send port, and to route data from said data receive port to said output port or to said data send port; a plurality of links, each establishing a data path from said output port of one of said channel devices to said input port of another one of said channel devices; and a processor connected to said channel devices, said processor controlling said signal routing arrangement of each channel device to provide automatic protection switching for said data communication node; said processor being configured to respond to channel performance metrics; and said channel performance metrics indicating whether said data communication node functions in a normal operating mode or in a protection mode; wherein, in said protection mode: one of said channel devices functions as a protection channel device, one of said channel devices is a protected channel device, and each of the remaining channel devices functions as a working channel device; said data receive port of said protection channel device receives a null data signal; said data receive port of said protected channel device receives a channel data signal; and, said processor controls said signal routing arrangement of each of said channel devices to route said null data signal to said input port of said protected channel device, and to route said channel data signal to said data send port of said protection channel device.