HP StorageWorks AG878A Multiplexer - 4 x - 1 Gbps Gigabit Ethernet. The HP StorageWorks Coarse Wave Division Multiplexer (CWDM) solution is a set of passive optical systems designed to provide optical network support for high-speed data Fibre Channel & Ethernet communication over Metropolitan Area Networks (MANs). This Multiplexer utilizes a set of eight CWDM optical wavelengths in either ring or point-to-point configurations. It is protocol independent; easy to operate with a reliable, low-maintenance design that uses no power supplies and no electronics.