XFP optical transceivers are hot-swappable and protocol-independent, 10 gigabit small form factor pluggables. Common applications for this form-factor include 10 Gigabit Ethernet, 10 Gbit/s Fibre channel, SONET, STM-64 and Optical Transport Network (OTN) OTU-2. They can operate over a single wavelength or use dense wavelength division multiplexing (DWDM).