Blsr Bandwidth; Figure; Four-Fiber Blsr Ring Switch; Two-Fiber Blsr Capacity - Cisco 15454-DS1-14= - 1.544Mbps Expansion Module Reference Manual

Chapter 12 SONET Topologies and Upgrades

Figure 12-6

Node 3

12.2.3 BLSR Bandwidth

BLSR nodes can terminate traffic coming from either side of the ring. Therefore, BLSRs are suited for
distributed node-to-node traffic applications such as interoffice networks and access networks.
BLSRs allow bandwidth to be reused around the ring and can carry more traffic than a network with
traffic flowing through one central hub. BLSRs can also carry more traffic than a path protection
configuration operating at the same OC-N rate.
of two-fiber BLSRs. The capacity is the OC-N rate divided by two, multiplied by the number of nodes
in the ring minus the number of pass-through STS-1 circuits.
Table 12-2
OC Rate
OC-12
OC-48
OC-192
1. N equals the number of ONS 15454 nodes configured as BLSR nodes.
2. PT equals the number of STS-1 circuits passed through ONS 15454 nodes in the ring (capacity can vary
Table 12-3
78-18106-01

Four-Fiber BLSR Ring Switch

Span 4
Span 5
Span 6
Span 3

Two-Fiber BLSR Capacity

Working Bandwidth
STS1-6
STS 1-24
STS 1-96
depending on the traffic pattern).
shows the bidirectional bandwidth capacities of four-fiber BLSRs.
Node 0
Span 8
OC-48 Ring
Span 7
Node 2
Table 12-2 shows the bidirectional bandwidth capacities
Protection Bandwidth
STS 7-12
STS 25-48
STS 97-192
Cisco ONS 15454 Reference Manual, R8.5
12.2.3 BLSR Bandwidth
Span 1
Node 1
Span 2
= Working fibers
= Protect fibers
Ring Capacity
1 2
6 x N – PT
24 x N – PT
96 x N – PT
12-9