Specifications

2-5
Cisco ONS 15530 Planning Guide
OL-7708-01
Chapter 2 Protection Schemes and Network Topologies
Splitter Based Facility Protection
2.5-Gbps ITU Trunk Card
With splitter protection, a passive optical splitter module on the 2.5-Gbps ITU line card duplicates the
ITU signal. The front panel of each splitter 2.5-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 2-3 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.
Figure 2-3 Splitter Protection with 2.5-Gbps ITU Trunk Cards
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.
10-port ESCON card
2.5-Gbps ITU trunk cards
2.5-Gbps ITU
transceiver
2.5-Gbps
aggregated
signal
OADM
modules
West
East
SRC
LRCLRC
85844
Active signal
Optical fiber
connection
Electrical backplane
connection
Standby
switch fabric
Active signal
Redundant
CPU switch
modules
Splitter module and
optical device