Cisco ONS 15454 DWDM - Chapter 10 Network Reference

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Cisco ONS 15454 DWDM Reference Manual, R8.5
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Chapter 10 Network Reference
10.1 Network Applications
10.1 Network Applications
Cisco ONS 15454 nodes can be provisioned for metro core DWDM network applications. Metro core
networks often include multiple spans and amplifiers, so the optical signal-to-noise ratio (OSNR) is the
limiting factor for channel performance.
Within DWDM networks, the ONS 15454 uses a communications protocol, called Node Services
Protocol (NSP), to communicate with other nodes. NSP automatically updates nodes whenever a change
in the network occurs. Each ONS 15454 DWDM node can:
• Identify other ONS 15454 DWDM nodes in the network.
• Identify the different types of DWDM networks.
• Identify when the DWDM network is complete and when it is incomplete.
10.2 Network Topologies
The ONS 15454 DWDM network topologies include ring networks, linear networks, and mesh networks.
10.2.1 Ring Networks
Ring networks support hubbed, multi-hubbed, any-to-any, and mesh traffic topologies.
10.2.1.1 Hubbed Traffic Topology
In the hubbed traffic topology (Figure 10-1), a hub node terminates all the DWDM channels. A channel
can be provisioned to support protected traffic between the hub node and any node in the ring. Both
working and protected traffic use the same wavelength on both sides of the ring. Protected traffic can
also be provisioned between any pair of optical add/drop multiplexing (OADM) nodes, except that either
the working or the protected path must be regenerated in the hub node.
Protected traffic saturates a channel in a hubbed topology, that is, no channel reuse is possible. However,
the same channel can be reused in different sections of the ring by provisioning unprotected multihop
traffic. From a transmission point of view, this network topology is similar to two bidirectional
point-to-point links with OADM nodes.
For more information about hub nodes, see the “9.1.1 Hub Node” section on page 9-2.