The newest wide adopted high speed interface for optical transceivers is the QSFP+ (Quad SFP+) that offers aggregated optical speeds of 40G. This is possible by simultaneously running four separate 10G channels and sum up the capacity into a single channel. The QSFP+ transceivers available on market are LR4 (10Km single-mode), IR4 (2Km single-mode) or eSR4 and SR4 for short haul multi-mode. The multi-mode solutions require special MPO fiber ribbons (multi-strand optical cables) able to transport the 4 different 10G optical connections. Single-mode solutions use only two strands of fiber and combine the 4 channels using inexpensive CWDM technology. This gives a tremendous advantage, simplifying the connectivity to standard LC optical connectors and thus reducing costs further.