The OC12 IR/STM4 SH 1310 card provides one intermediate or short 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.