C H A P T E R 1

Product Technology

This chapter presents the general system technology and the available protection architectures for Cisco’s dense wavelength division multiplexing (DWDM) metro system, the Cisco ONS 15200.

1.1 Optical System Description

The ONS 15200 DWDM metro system transports data over wavelengths using fiber-optic cables. The ONS 15200 operates in the 1550 nm transmission window. Over a single optical fiber pair, the ONS

15200 can carry up to sixteen channels of data in the following bit rates and formats:

155 Mbps – SONET OC-3 or SDH STM-1

622 Mbps – SONET OC-12 or SDH STM-4

2.5 Gbps – SONET OC-48 or SDH STM-16

100 Mbps – 1.25 Gbps, pass-through mode/2R operation Protected or unprotected data can transmit over the ONS 15200.

The optical layer is independent of the electronic protocol that is external to the ONS 15200 system. You can use any higher-level protocol, including proprietary products, within the ONS 15200 system. Any protocol used must fulfill the requirements listed in this book, including the bit rates listed in this section.

1.2 Optical Channels

In the ONS 15200 system, optical channels transport information between two client-layer interface ports. All optical channels in the ONS 15200 system are duplex channels, which means that traffic flows in both directions. The optical channels can be unprotected, as described in the “Unprotected Channels” section on page 1-1, or protected, as described in the “Protected Channels” section on page 1-2.

1.2.1 Unprotected Channels

In an unprotected channel, protection fiber is not available. Only one fiber sends traffic to the client layer of the receiving node. You can use unprotected channels where protection is not needed or if the client layer provides protection. Cisco recommends that you only use protection in one layer and avoid

Cisco ONS 15200 Product Description

 

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Cisco Systems ONS 15200 manual Optical System Description, Optical Channels, Unprotected Channels