62Glossary

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.

212257-B

Page 62
Image 62
Nortel Networks 10292FA, 10396EA manual An optical wavelength band for WDM optical communications