Specifications

39
Cisco ONS 15454 Product Overview, R3.3
May 2002
Cisco ONS 15454 Product Overview
Network Configuration
Figure 22 shows a basic UPSR configuration. If Node ID 0 sends a signal to Node ID
2, the working signal travels on the working traffic path through Node ID 1. The same
signal is also sent on the protect traffic path through Node ID 3. If a fiber break occurs,
Node ID 2 switches its active receiver to the protect signal coming through Node ID 3.
Figure 22 Unidirectional path switched ring
Bidirectional Line Switched Ring
The ONS 15454 supports two-fiber and four-fiber BLSRs with up to 16 ONS 15454
nodes. BLSRs work well for distributed traffic applications, such as interoffice
networks.
Two-fiber BLSRs allocate half the available fiber bandwidth for protection. In a
two-fiber OC-48 BLSR, for example, STSs 1–24 are allocated to working traffic,
and STSs 25–48 are allocated for protection. If a break occurs on one fiber,
working traffic switches to the protection bandwidth (STSs 25–48) on the other
ONS 15454
Node ID 0
ONS 15454
Node ID 1
ONS 15454
Node ID 2
ONS 15454
Node ID 3
32148
= Fiber 1
= Fiber 2