Small form-factor pluggable interface
The SFP interface (Small Form Factor Pluggable interface) is an industry standard daughter card used in networking devices (esp. those by Cisco). It essentially interfaces a network device mother board (for a router or similar device) with a fibre optic cable using an SFF Connector. Such boards can carry data at speeds of around 5GBit/s. Their main advantage is that new speeds can be interfaced to an expensive network device by changing only the SFP module.
See also
Categories: Computer hardware stubs | Fiber optics