The Cisco ONS 15454 12-Port and 4-Port SFP-Based Multirate Optics Card (MRC-12 and MRC-4) supports multiple Small Form-Factor Pluggable (SFP) modules, helping enable multirate SONET/SDH and multiple-reach capabilities. The MRC-12 card (Figure 1) operates in either Cisco ONS 15454 SONET or SDH systems, supporting optical line rates including OC-3/STM-1, OC-12/STM-4, and OC-48/STM-16 and optical reaches from short-reach/interoffice to long-reach/long-haul, including dense wavelength-division multiplexing (DWDM) and coarse wavelength-division multiplexing (CWDM). There are two versions of the MRC-12 card for SDH systems, limited to 10 Gbps and 2.5 Gbps of bandwidth capacity, respectively. The MRC-4 (Figure 2) operates only in Cisco ONS 15454 SONET systems, but at the same optical line rates and optical reaches, with up to 2.5 Gbps bandwidth.