Specifications

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Cisco ONS 15530 Planning Guide
OL-7708-01
Chapter 2 Protection Schemes and Network Topologies
Splitter Based Facility Protection
A switchover is triggered in hardware by a loss of light on the receive signal. Switchovers for signal
degrade or signal failure are configurable in the software.
Splitter Protection Considerations When Using Transponder Line Cards
The following considerations apply when using splitter protection with transponder line cards:
• Because the signal splitter module on splitter transponder line cards introduces 3.55 dB of loss in
the transmit direction, we recommend using nonsplitter transponder line cards for configurations
where splitter protection is not required.
• The APS software that supports splitter protection can be configured as revertive or nonrevertive.
Unless a switchover request from the CLI (command-line interface) is in effect, the system uses the
working interface for the active signal. After a system-initiated switchover to the protection
interface occurs for signal quality reasons, the active traffic can be put back on the previously failed
working fiber after the fault has been remedied. The fault can be remedied either automatically
(revertive) or through manual intervention (nonrevertive).
• Up to four channels can be splitter protected on a single shelf.
For rules on 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.
8-Port Multi-Service Muxponders
With splitter protection, a passive optical splitter module on the 8-port multi-service muxponder
duplicates the ITU signal. The front panel of each splitter 8-port multi-service muxponder has
connectors for two fiber pairs for cabling to the two OADM modules. One fiber pair serves as the active
connection, while the other pair serves as the standby. The signal is transmitted on both connections, but
in the receive direction, an optical switch selects one signal to be the active one. If a failure is detected
on the active receive signal, a switchover to the standby receiver signal occurs under control of the LRC
(line card redundancy controller). Assume, for example, that if the active signal in Figure 2-1 is on the
east interface, a failure of the signal on that fiber would result in a switchover, and the signal on the west
interface would be selected for the receive signal. You can configure preferred working and protection
interfaces in the software for the system to use for the active and standby signals, as the signal quality
allows.