HANOVER, Md.--(BUSINESS WIRE)--Ciena® Corporation (NYSE: CIEN), the network specialist, has entered into a definitive agreement to acquire Cyan Inc. (NYSE: CYNI), a leading provider of next-generation software and platforms to enable open, agile and scalable software-defined networks. Under the terms of the agreement, Ciena will acquire all of the outstanding shares of Cyan in a cash and stock transaction currently valued at approximately $400 million (or $335 million, net of estimated cash acq