C Form-factor Pluggable
The C form-factor pluggable (CFP) is a multi-source agreement to produce a common form-factor for the transmission of high-speed digital signals. The c stands for the Latin letter C used to express the number 100 (centum), since the standard was primarily developed for 100 Gigabit Ethernet systems.
CFP standardization
The CFP transceiver is specified by a multi-source agreement (MSA) among competing manufacturers. The CFP was designed after the small form-factor pluggable transceiver (SFP) interface, but is significantly larger to support 100 Gbit/s. While the electrical connection of a CFP uses 10 × 10 Gbit/s lanes in each direction (RX, TX),[1] the optical connection can support both 10 × 10 Gbit/s and 4 × 25 Gbit/s variants of 100 Gbit/s interconnects (typically referred to as 100GBASE-SR10 in 100 meter MMF, 100GBASE-LR10 and 100GBASE-LR4 in 10 km SMF reach, and 100GBASE-ER10 and 100GBASE-ER4 in 40 km SMF reach respectively.)[2]
In March 2009, Santur Corporation demonstrated a 100 Gigabit pluggable CFP transceiver prototype.[3]
Supported signals
CFP transceivers can support a single 100 Gbit/s signal like 100GbE or OTU4 or one or more 40 Gbit/s signals like 40GbE, OTU3, or STM-256/OC-768.
Variants
The original CFP specification was proposed at a time when 10 Gbit/s signals were far more achievable than 25 Gbit/s signals. As such to achieve 100 Gbit/s line rate, the most affordable solution was based on 10 lanes of 10 Gbit/s. However, as expected, improvements in technology have allowed higher performance and higher density. Hence the development of the CFP2 and CFP4 specifications. While electrically similar, they specify a form-factor of 1/2 and 1/4 respectively in size of the original specification. Note that CFP, CFP2 and CFP4 modules are not interchangeable (but are inter-operable at the optical interface with appropriate connectors).
CFP
- 82 mm nominal width
- 148 pin electrical connection
- integrated digital signal processor within package
- less than 24 W power usage
- 10×10G or 4×25G lanes
CFP2
- 41.5 mm nominal width
- 104 pin electrical connection
- no digital signal processor in package, relies on host card
- less than 12 W power usage
- 10×10G, 4×25G, 8×25G, or 8×50G lanes
CFP4
- 21.5 mm nominal width
- 56 pin electrical connection
- no digital signal processor in package, relies on host card
- less than 6 W power usage
- 10×10G or 4×25G lanes
MSA 5″×7″ (Gen 1)
- 168 pin electrical connection (designed to be built into a line card)
- digital signal processor within package
- less than 80 W power usage
MSA 4″×5″ (Gen 2)
- 168 pin electrical connection (designed to be built into a line card)
- digital signal processor within package
- less than 40 W power usage
See also
References
- 1 2 "CFP MSA Hardware Specification, Rev. 1.4" (PDF). Retrieved 2010-07-02.
- ↑ "Operational Considerations for Deploying 100 Gigabit Ethernet" (PDF). Retrieved 2012-01-12.
- ↑ "Santur Delivers the World's First 100Gb/s Transceiver Platform for Client Connectivity Based on Photonic Intelligent Integration". news release. March 23, 2009. Archived from the original on July 20, 2009. Retrieved May 27, 2013.
- ↑ "CFP2 MSA Hardware Specification, Rev. 1.0" (PDF). Retrieved 2015-04-17.
- ↑ "CFP4 MSA Hardware Specification, Rev. 1.0" (PDF). Retrieved 2015-05-06.
- ↑ "Optical Integration and the Role of DSP in Coherent Optics Modules" (PDF). Retrieved 2015-04-17.
- ↑ "Multisource Agreement for Generation 2.0 100G Long-Haul DWDM Transmission Module – Electromechanical" (PDF). Retrieved 2015-04-17.