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Cisco ONS 15454 SDH Reference Manual, R5.0
April 2008
Chapter11 SDH Topologies and Up grades
11.4.1 MS-SPRing DR I
Figure 11-18 shows ONS 15454 SDHs in a traditional MS-SPRing DRI topology with same-side
routing. In Ring 1, Nodes 3 and 4 are the interconnect n odes, and in Ring 2, Nodes 8 and 9 are the
interconnect nodes. Duplicate signals are sent between Node 4 (Ring 1) and Node 9 (Ring 2), and
between Node 3 (Ring 1) and Node 8 (Ring 2). The primary nodes (Nodes 4 and 9) a re on the same side,
and the secondary nodes (Nodes 3 and 8) provide an alternative route. In Ring 1, traffic at Node 4 is
dropped (to Node 9) and continued (to Node 10). Similarly, at Node 9, traffic is dropped (to Node 4) and
continued (to Node 5).
Figure11-18 ONS 15454 SDH Traditional MS-SPRing Dual Ring Interconnect (Same-Side Routing)
Service Selector
Secondary Path
Primary Path, Drop and Continue to Bridge
Drop and Continue
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MS-SPRing
Ring 1
Primary
Node
Secondary
Node
Node 5
Node 4 Node 3
Node 9 Node 8
Node 1
Node 2
MS-SPRing
Ring 2
Primary
Node
Secondary
Node
Node 10
Node 6
Node 7