C H A P T E R
F I N A L D R A F T - C I S C O C O N F I D E N T I A L
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Cisco ONS 15216 EDFA2 Operations Guide
78-16033-01
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Applications
This manual describes how to install and operate the Cisco Optical Network System (ONS) 15216
Erbium-Doped Fiber Amplifier 2 (EDFA2). The ONS 15216 EDFA2 is an optical amplifier that enables
the migration to next-generation all-optical networks. It features bandwidth-on-demand and wavelength
protection switching that extend dense wavelength division multiplexing (DWDM) links by hundreds of
kilometers.
With the ONS 15216 EDFA2, optical signals from a span in a DWDM network can be added or dropped
without negatively affecting (degrading) other optical signals on the same span.
1.1 Bandwidth On Demand
The ONS 15216 EDFA2 is a technology for bandwidth-on-demand wavelength services. Depending on
the settings and the input power, every wavelength in a ONS 15216 EDFA2 is guaranteed to be amplified
by 13 to 22 dB. With the ONS 15216 EDFA2’s 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 (composite) input power of all wavelengths is between 4 dBm and –27 dBm, any number
of wavelengths can be amplified.
1.2 Wavelength Protection Switching
The ONS 15216 EDFA2 uses wavelength protection switching to restore wavelengths that are lost in the
event of a fiber cut or other loss of signal.
Figure 1-1 on page 1-2
shows an example of wavelength
protection switching. In this example, two wavelengths are routed clockwise around a metro ring, and
two wavelengths are routed counter-clockwise around the same ring. Of the two counter-clockwise
wavelengths, only one transits the span linking locations D and C. If a fiber cut occurred on this span,
the affected wavelength could be restored by rerouting it (clockwise) around the ring to location D.
Wavelength protection switching minimizes the amount of bandwidth allocated for restoration because
only the affected wavelength is restored, not the entire fiber.
