The Cisco CWDM is passive device that provide the capability to multiplex and demultiplex, This device allows you to multiplex and demultiplex eight separate channels onto one pair of fiber. Dual fiber is used for both network and SFP connections.
The 8-Channel Multiplexer/Demultiplexer (CWDM-MUX-8A) allows you to multiplex/demultiplex eight separate channels into one pair of fiber. Dual fiber is used for both the network connection and the CWDM GBIC or CWDM SFP transceiver connections. The eight available wavelengths are 1470-nm, 1490-nm, 1510-nm, 1530-nm, 1550-nm, 1570-nm, 1590-nm, and 1610-nm. The multiplexer/demultiplexer, is equipped with a monitor port that allows you to attach a power meter or an optical spectrum analyzer to assist you in monitoring and troubleshooting the network.