Specifications

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Cisco ONS 15530 Planning Guide
OL-7708-01
Chapter 2 Protection Schemes and Network Topologies
Y-Cable Based Line Card Protection
• The OSC and the in-band message channel play a crucial role in splitter based protection by
allowing the protection fiber to be monitored for interruption of service.
• Up to four channels can be splitter protected on a single shelf if the OSC is not supported; if the OSC
is supported, up to three channels can be splitter protected on a single shelf.
For example of how to configure the shelf for splitter protection, see Chapter 6, “Example Shelf
Configurations and Topologies.” For instructions on configuring the software for splitter protection,
refer to the Cisco ONS 15530 Configuration Guide.
Y-Cable Based Line Card Protection
The Cisco ONS 15530 supports line card protection for transponder line cards, 4-port 1-Gbps/2-Gbps
FC aggregation cards, and 8-port Fibre Channel/Gigabit Ethernet aggregation cards, using a Y-cable
scheme. Y-cable protection protects against both facility failures and failure of the line cards. Using an
external 2:1 combiner cable (the Y-cable) between the client equipment and the line card interfaces, the
client signal is duplicated and sent to two line card interfaces. This arrangement is illustrated in
Figure 2-5.
Figure 2-5 Example Y-Cable Protection Scheme Using Transponder Line Cards
In Y-cable protected configurations, one of the line cards functions as the active and the other as the
standby. On the active line card, all the lasers and receivers are sending and receiving the client signal.
On the standby line card, however, the client side laser is turned off to avoid corrupting the signal
transmitted back to the client equipment. The performance monitor on the active line card optically
monitors the signal received from the trunk side. If loss of light, signal failure, or signal degrade is
OADM
modules
West
East
SRC
LRC
Client optics
ITU optics
Performance
monitor
CPU
LRC
LRC
LRCLRC
OSC
OSC
Redundant
CPU switch
modules
Optical
fiber
connection
Electrical
backplane
connection
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Transponder
line cards