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Cisco ONS 15310-MA SDH Reference Manual, Release 9.1 and Release 9.2
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Chapter 9 SDH Topologies and Upgrades
Four Node Configurations
Figure 9-10 Virtual Ring for ONS 15310-MA SDH
9.5 Four Node Configurations
You can link multiple ONS 15310-MA SDH nodes using their STMN ports (also known as creating a
fiber-optic bus) to accommodate more access traffic than a single ONS 15310-MA SDH can support.
You can link nodes with STMN fiber spans as you would link any other two network nodes. The nodes
can be grouped in one facility to aggregate more local traffic.
9.6 STMN Speed Upgrades
A span is the optical fiber connection between two ONS 15310-MA SDH nodes. In a span (optical speed)
upgrade, the transmission rate of a span is upgraded from an STM1 to STM4 signal (ONS 15310-MA
SDH), from an STM4 to STM16 signal (ONS 15310-MA SDH only), or from an STM1 to STM16 signal
(ONS 15310-MA SDH only), but all other span configuration attributes remain unchanged. With
multiple nodes, a span upgrade is a coordinated series of upgrades on all nodes in the ring or protection
group. The ONS 15310-MA SDH nodes support the span upgrade wizard if you are upgrading two
ONS 15310-MAs with 1+1 protection from STM1 to STM4, STM4 to STM16, or STM1 to STM16.
To perform a span upgrade, the higher-rate pluggable port module (PPM) must replace the lower-rate
PPM in the same slot. If you are using a multi-rate PPM, you do not need to physically replace the PPM.
All spans in the network must be upgraded. The 1+1 protection configuration of the original lower-rate
PPM is retained for the higher-rate PPM.
When performing span upgrades, Cisco recommends that you upgrade all spans in a network
consecutively and in the same maintenance window. Until all spans are upgraded, mismatched PPM
types will be present.
If you are upgrading two ONS 15310-MA SDH nodes with 1+1 protection from STM1 to STM4, STM4
to STM16, or STM1 to STM16, Cisco recommends using the Span Upgrade Wizard to perform span
upgrades. Although you can also use the manual span upgrade procedures, the manual procedures are
STM16 STM4STM4
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ONS 1510-MA
Node 1
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Node 6
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Node 2
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Node 7