The CFP (C Form-factor Pluggable, where C stands for Centum, hundred) MSA is the first industry standard for pluggable 40Gbps and 100Gbps optical transceivers for telecom and datacom application.
CFP transceivers support various protocols (such as 40GbE, 100GbE, OC-768/STM-256, OTU4), media types (multimode and single mode fiber optics and also DWDM). Link distances reach from a few metres to 40km (and beyond). While the electrical connection is based at 4 lanes at 10Gbps (for 40G), respectively 10 x 10 Gbps (for 100G) in each direction, the optical interfaces vary, from supporting duplex single-mode fibers to fiber-ribbons.
The QFSP form factor is the second-generation industry standard for pluggable 40Gbps optical transceivers. Size and power dissipation are significantly reduced compared to first generation CFP.
40G QSFP are available as SR4 (Multimode up to 100/150meters) and LR4 (Single Mode up to 10km) version. LR4 version uses 4 x 10Gbps CWDM wavelength in 1270nm-1330nm range and can be combined with SOA for range extension.