Specifications

CHAPTER
2-1
Cisco ONS 15530 Planning Guide
OL-7708-01
2
Protection Schemes and Network Topologies
This chapter describes how protection is implemented on the Cisco ONS 15530. It also describes the
supported network topologies and how protection works in these topologies. This chapter contains the
following major sections:
• About Protection Against Fiber and System Failures, page 2-1
• Splitter Based Facility Protection, page 2-2
• Y-Cable Based Line Card Protection, page 2-8
• Client Based Line Card Protection, page 2-9
• Switch Fabric Based Line Card Protection, page 2-13
• Trunk Fiber Based Protection, page 2-16
• Supported Topologies, page 2-17
About Protection Against Fiber and System Failures
The design of the Cisco ONS 15530 provides the following levels of 1+1 protection:
• Facility protection provides protection against failures because of fiber cuts or unacceptable signal
degradation on the trunk side.
• Client based line card protection provides protection against failures on the fiber, the line cards,
(which contain the light emitting and light detecting devices), the 3R (reshape, retime, retransmit)
electronics, and the client equipment.
• Y-cable based line card protection provides protection against failures both on the fiber, and in the
line cards (which contain the light emitting and light detecting devices), and the 3R electronics.
• Switch fabric based line card protection provides protection against channel signal failures in switch
fabric cross connections, ITU and uplink cards, and the fiber.
• Trunk fiber based protection provides protection against trunk fiber cuts.