Cisco ONS 15454 DWDM - Meshed Rings

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Cisco ONS 15454 DWDM Installation and Operations Guide, R6.0
August 2005
Chapter 18 Network Reference
18.2.4 Meshed Rings
Figure 18-3 Any-to-Any Ring
18.2.4 Meshed Rings
The meshed ring topology (Figure 18-4) does not use hubbed nodes; only amplified and passive OADM
nodes are present. Protected traffic can be provisioned between any two nodes; however, the selected
channel cannot be reused in the ring. Unprotected multihop traffic can be provisioned in the ring. A
meshed ring must be designed to prevent amplified spontaneous emission (ASE) lasing. This is done by
configuring a particular node as an anti-ASE node. An anti-ASE node can be created in two ways:
• Equip an OADM node with 32MUX-O cards and 32DMX-O cards. This solution is adopted when
the total number of wavelengths deployed in the ring is higher than ten. OADM nodes equipped with
32MUX-O cards and 32DMX-O cards are called full OADM nodes.
• When the total number of wavelengths deployed in the ring is lower than ten, the anti-ASE node is
configured by using an OADM node where all the channels that are not terminated in the node are
configured as “optical pass-through.” In other words, no channels in the anti-ASE node can travel
through the express path of the OADM node.
For more information about OADM nodes, see the “17.1.3 OADM Node” section on page 17-4. For
more information about anti-ASE nodes, see the “17.1.5 Anti-ASE Node” section on page 17-10.
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