The OC12 IR/STM4 SH 1310 card provides one intermediate or short range, ITU-T G.707, ITU-T G.957-compliant, SDH STM-4 port per card. The interface operates at 622.08 MBits/s (Mbps) over a single-mode fiber span. The card supports concatenated or non-concatenated payloads on a per VC-4 basis.