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5-28
Cisco ONS 15454 Installation and Operations Guide
78-13453-01
Chapter 5 SONET Topologies
Unidirectional Path Switched Rings
5.3.1 Example UPSR Application
Figure 5-22
shows a common UPSR application. OC-3 optics provide remote switch connectivity to a
host TR-303 switch. In the example, each remote switch requires eight DS-1s to return to the host switch.
Figure 5-23
and
Figure 5-24
show the shelf layout for each site.
Figure 5-22 An OC-3 UPSR
Node ID 0 has four DS1-14 cards to provide 56 active DS-1 ports. The other sites only require two
DS1-14 cards to handle the eight DS-1s to and from the remote switch. You can use the other half of
each ONS 15454 shelf assembly to provide support for a second or third ring to other existing or planned
remote sites.
In this sample OC-3 UPSR, Node ID 0 contains four DS1-14 cards and two OC3 IR 4 1310 cards. Six
free slots also exist in this setup and can be provisioned with cards or left empty.
Figure 5-23
shows the
shelf setup for these cards.
8 DS-1s
8 DS-1s
8 DS-1s
TR-303
Switch
32149
ONS 15454
Node ID 0
ONS 15454
Node ID 1
ONS 15454
Node ID 2
ONS 15454
Node ID 3
= Fiber 1
= Fiber 2