Cisco ONS 15600 Reference Manual page 156

8.3.1 Two-Fiber MS-SPRings
Figure 8-3
Node 3
Figure 8-4
• All circuits originating on Node 0 that carried traffic to Node 2 on Fiber 2 are switched to the protect
bandwidth of Fiber 1. For example, a circuit carried on VC4-1 on Fiber 2 is switched to VC4-9 on
Fiber 1. A circuit carried on VC4-2 on Fiber 2 is switched to VC4-10 on Fiber 1. Fiber 1 carries the
circuit to Node 3 (the original routing destination). Node 3 switches the circuit back to VC4-1 on
Fiber 2 where it is routed to Node 2 on VC4-1.
Circuits originating on Node 2 that normally carry traffic to Node 0 on Fiber 1 switch to the protect
•
bandwidth of Fiber 2 at Node 3. For example, a circuit carried on VC4-2 on Fiber 1 is switched to
VC4-10 on Fiber 2. Fiber 2 carries the circuit to Node 0 where the circuit is switched back to VC4-2
on Fiber 1 and then dropped to its destination.
Cisco ONS 15600 SDH Reference Manual, Release 9.0
8-4
Four-Node, Two-Fiber MS-SPRing Traffic Pattern Sample
Node 0
STM-16 Ring
Node 2
shows how traffic is rerouted following a line break between Node 0 and Node 3.
Chapter 8 SDH Topologies and Upgrades
Node 1
Traffic flow
Fiber 1
Fiber 2
78-18400-01