A SFP (Small Form-Factor Pluggable) transceiver is a compact, hot-swappable device that can be used for both transmit and receive data and also plugs into a physical port of a network device.  It is used in the communication network and has a transmitting side and receiving side. The SFP transceiver has a laser which communicates with the receiving side of the other optic on the other side. SFP transceivers are designed to support several communication standards including SONET, Gigabit Ethernet and Fibre Channel, and their interfaces on a networking device such as a router provides a modular device that can be freely adjusted to fiber optic and copper networking specifications.