The Cisco ONS 15501 is a low-noise, gain-flattened C-band optical erbium doped fiber amplifier (EDFA) designed to extend the distance of today's high-speed optical infrastructure. The Cisco ONS 15501 complements the Cisco ONS 15500 dense wavelength-division multiplexing (DWDM) solution, providing customers with the capability to extend their 100GHz, 32-channel, 2.5Gbps, or 10Gbps optical infrastructure over greater distances. Furthermore, the Cisco ONS 15501 integrates seamlessly with the Cisco Catalyst 6500 Series, Cisco 7600 Series, and Cisco 12000 Series to provide inter-point-of-presence (POP) extension and the interconnection of remote campuses over 10 Gigabit Ethernet or SONET/SDH OC-192/STM-64. Packaged in a one-rack-unit (1RU) chassis, the Cisco ONS 15501 incorporates features such as 17dB constant flat gain, automatic gain control (AGC), and low noise figure for excellent optical signal-to-noise ratio (OSNR) characteristics.