The OC12 LR/STM4 LH 1550 card provides one long-range SONET/SDH OC-12 port compliant with the International Telecommunication Union's G.707, G.957, and Telcordia's GR-253. The port operates at 622.08 Mbps over a single-mode fiber span. The card supports VT and non-concatenated, or concatenated payloads at STS-1, STS-3c, STS-6c, or STS-12c signal levels.You can install the OC12 LR/STM4 LH 1550 card in any multispeed card slot. The OC12 LR/STM4 LH 1550 can be provisioned as part of a two-fiber BLSR, UPSR or linear ADM. The OC12 LR/STM4 LH 1550 uses long-reach optics centered at 1550 nm and contains a transmit and receive connector (labeled) on the card faceplate. The OC12 LR/STM4 LH 1550 uses SC optical connections and supports 1+1 bidirectional or unidirectional protection switching. The OC12 LR/STM4 LH 1550 detects LOS, LOF, LOP, AIS-L, and RDI-L conditions. The card also counts section and line BIT errors.