5-23
Cisco ONS 15454 Installation and Operations Guide
November 2001
Chapter 5 SONET Topologies
Bidirectional Line Switched Rings
Figure 5-17
shows a four node OC-48 BLSR using trunk cards in Slots 6 and 12 at all four nodes. Trunk
cards will be moved at Node 4 from Slots 6 and 12 to Slots 5 and 6. To do this Node 4 is temporarily
removed from the active BLSR while the trunk cards are switched.
Figure 5-17 A four-node BLSR before a trunk card switch
Figure 5-18
shows the BLSR after the cards are switched.
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Node 1
Node 4
Node 3
Node 2
Slot 12 (East)
Slot 6 (West)
Slot 12 (East)
Slot 6 (West)
Slot 12 (East)
Slot 6 (West)
Slot 12 (East)
Slot 6 (West)