Specifications

2-6
Cisco ONS 15530 Planning Guide
OL-7708-01
Chapter 2 Protection Schemes and Network Topologies
Splitter Based Facility Protection
Splitter Protection Considerations When Using 2.5-Gbps ITU Line Cards
The following considerations apply when using splitter protection:
• Because the signal splitter module on splitter 2.5-Gbps ITU line cards introduces 3.55 dB of loss in
the transmit direction, we recommend using nonsplitter 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).
• 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.
10-Gbps ITU Tunable and Non tunable Trunk Card
With splitter protection, a passive optical splitter module on the 10-Gbps ITU line card duplicates the
ITU signal. The front panel of each splitter 10-Gbps ITU line card 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 2-4 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.