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18-2
Cisco ONS 15454 DWDM Installation and Operations Guide, R6.0
August 2005
Chapter 18 Network Reference
18.2 Network Topologies
18.2 Network Topologies
The ONS 15454 DWDM network topologies include hubbed, multihubbed, and meshed rings, and linear
and single-span networks.
18.2.1 Hubbed Rings
In the hubbed ring topology (
), 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 ring, 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
“17.1.1 Hub Node” section on page 17-1
Figure 18-1
Hubbed Ring
18.2.2 Multihubbed Rings
A multihubbed ring (
) is based on the hubbed ring topology, except that two or more hub
nodes are added. Protected traffic can only be established between the two hub nodes. Protected traffic
can be provisioned between a hub node and any OADM node only if the allocated wavelength channel
Hub
Amplified OADM
Passive OADM
Line amplifier
90995
Amplified OADM
Passive OADM
Amplified OADM
OSC
OSC
Summary of Contents for ONS 15454 DWDM
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