The Cisco ONS 15216 erbium-doped fiber amplifier 2 (EDFA2) is an optical amplifier that enables the migration to next generation all-optical networks. The EDFA2 enables bandwidth-on-demand and wavelength protection switching that extend dense wavelength division multiplexing (DWDM) links by hundreds of kilometers. Using the ONS 15216 EDFA2, you can add or drop optical signals from a span in a DWDM network without negatively affecting (degrading) the other optical signals on the same span.The ONS 15216 EDFA2 is a technology for bandwidth-on-demand wavelength services. Depending on the settings and the input power, every wavelength in an ONS 15216 EDFA2 is guaranteed to be amplified by 13 to 22 dB. With ONS 15216 EDFA2 gain control technology, amplification for each wavelength remains constant at all times as wavelengths are added or dropped from an optical fiber. As long as the total input power of all wavelengths is between 4 dBm and -27 dBm, any number of wavelengths can be amplified.