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7. Optical Carriers

Short for Optical Carrier, used to specify the speed of fiber optic networks conforming to the SONET standard. The table shows the speeds for common OC levels.

Optical Carrier Speed
OC-1 51.85 Mbps
OC-3 155.52 Mbps
OC-9 466.56 Mbps
OC-12 622.08 Mbps
OC-19 933.12 Mbps
OC-24 1.244 Gbps
OC-36 1.866 Gbps
OC-48 2.488 Gbps
OC-96 4.977 Gbps
OC-192 9.953 Gbps
OC-768 40 Gbps
OC-3072 160 Gbps

Each channel is 51.85 Mbps. An OC-3, for example, has 3 channels adding up to 155.52 Mbps.

Currently, Cisco CRS-1 System features OC-768 line cards. These cards are priced at $2,000,000 USD each.

by redxii See Profile edited by Oxygen See Profile
last modified: 2005-01-20 01:51:30

Short for Dense Wavelength Division Multiplexing, an optical technology used to increase bandwidth over existing fiber optic backbones.

DWDM works by combining and transmitting multiple signals simultaneously at different wavelengths on the same fiber. In effect, one fiber is transformed into multiple virtual fibers. So, if you were to multiplex eight OC -48 signals into one fiber, you would increase the carrying capacity of that fiber from 2.5 Gb/s to 20 Gb/s. Currently, because of DWDM, single fibers have been able to transmit data at speeds up to 400Gb/s. And, as vendors add more channels to each fiber, terabit capacity is on its way.

A key advantage to DWDM is that it's protocol and bit-rate independent. DWDM-based networks can transmit data in IP, ATM, SONET /SDH, and Ethernet, and handle bit-rates between 100 Mb/s and 2.5 Gb/s. Therefore, DWDM-based networks can carry different types of traffic at different speeds over an optical channel.


by redxii See Profile
last modified: 2002-07-07 19:55:20