Nortel 10292FA, Руководство по установке

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62 Glossary
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each signal level thereafter operates at a speed divisible by that number. For
example, OC-3 operates at 155.52 Mbit/s.
OC-1
optical carrier - level 1
An optical SONET signal at 51.84 Mbit/s.
OC-3
optical carrier - level 3
An optical SONET signal at 155.52 Mbit/s.
OC-12
optical carrier - level 12
An optical SONET signal at 622.08 Mbit/s.
OMUX
optical multiplexer
An optical multiplexer/demultiplexer that multiplexes and demultiplexes four
or eight CWDM wavelength channels from a two-fiber circuit.
optical channel
An optical wavelength band for WDM optical communications.
optical fiber
Very thin strands of pure silica glass through which laser light travels in an
optical network. Consists of a core surrounded by a less refractive index
cladding.
optical seam
An optical seam occurs at any site in a network when there is no optical
passthrough, that is, where information is dropped from but not added onto
the ring.
Optical Time Domain Reflectometer (OTDR)
Device used to inspect optical fiber links by sending optical pulses down them
and monitoring the light reflected back to the device. Can calculate overall
fiber attenuation and highlight points of loss in the fiber, or even fiber breaks.