An optical cross-connect includes multiple input ports that each receives an optical input signal and multiple output ports that each output an optical output signal. The optical cross-connect also includes a distributing amplifier associated with each input port that generates multiple copies of the input signal received at the associated input port and multiple filter units that receive one or more of the copies and forward traffic in selected channels of particular copies. In addition, the optical cross-connect includes a combining amplifier associated with each output port that receives the traffic forwarded by one or more of the filter units and combines the received traffic into an output signal. Moreover, the optical cross-connect includes at least one upgrade input port and at least one upgrade output port expanding the capacity of the optical cross-connect, as well as associated upgrade distributing and combining amplifiers and upgrade filter units.