Specifications

5-18
Cisco ONS 15454 Installation and Operations Guide, R3.2
March 2002
Chapter 5 SONET Topologies
Bidirectional Line Switched Rings
Step 8 Clear the span lockout:
a. Display a BLSR node in node view. Click the Maintenance > Ring tabs.
b. Under West Switch, select CLEAR. Click Apply
c. Under East Switch, select CLEAR. Click Apply.
d. Repeat Steps a – c at each node in the new four-fiber BLSR.
e. Switch to network view. Verify that no critical or major alarms are present, nor any facility alarms,
such as LOS, LOF, AIS-L, SF, and SD. If an alarm is present, resolve the problem using procedures
in the Cisco ONS 15454 Troubleshooting and Maintenance Guide.
Step 9 Test the four-fiber BLSR using procedures in Step 11 in the “Provision the BLSR” procedure on
page 5-15.
5.2.8 Adding and Removing BLSR Nodes
This section explains how to add and remove BLSR nodes. To add or remove a node, you force a
protection switch to route traffic away from the span where you will add or remove the node. Figure 5-16
shows a three-node BLSR before the new node is added. To add Node 3, you would:
• Force a protection switch on the Node 1 (Slot 5, West) and Node 4 (Slot 12, East) span. The
protection switch forces traffic away from the fibers that you will remove and reconnect to the added
node.
• Remove fibers from Node 1/Slot 5 and Node 4/Slot 12, then, using additional fibers, connect Node
1 and Node 4 to Node 3.
• Remove the protection switch to route traffic through the added node.
Note You can only add one node at a time to an ONS 15454 BLSR.