VDF-200 serial Voice Distribution Frame is composed of VDF-200 Voice Distribution unit and sub-rack, and can be set in the 19 inches rack, 6U in height, 300nm in depth. With a standard Cologne board module, the capacity of each unit is 200/400 return wires. Preparation Security unit and the connection-recording card is offered. It can be used with small capacity switchboard, PCM or carrier.