Chapter 8
SONET Topologies and Upgrades
Figure 8-4
Node 3
8.3.2 Four-Fiber BLSRs
Four-fiber BLSRs double the bandwidth of two-fiber BLSRs. Because they allow span switching as well
as ring switching, four-fiber BLSRs increase the reliability and flexibility of traffic protection. Two
fibers are allocated for working traffic and two fibers for protection, as shown in
implement a four-fiber BLSR, you can install either two or four OC-48 or OC-192 cards at each BLSR
node.
Four-Node, Two-Fiber BLSR Traffic Pattern Following Line Break
Node 0
OC-48 Ring
Node 2
8.3.2 Four-Fiber BLSRs
Node 1
Traffic flow
Fiber 1
Fiber 2
Figure
Cisco ONS 15600 Reference Manual, R6.0
8-5. To
8-5