Method and apparatus for performing group switching in dense wavelength division multiplexing optical networks

Method and apparatus for performing group switching in DWDM optical networks are described. One embodiment is an NxN three-stage group connector with N inputs and N outputs, wherein the N outputs are divided into r output groups, each group including n outputs such that r = N/n. The group connector comprises a first stage comprising r nxm crossbar switch modules, wherein m ≥ n-1; a second stage comprising m rxr crossbar switch modules; and a third stage comprising r MxN concentrator switch modules.