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Software Configuration Guide—Release 15(02)SG
OL-23818-01
Chapter 5 Configuring the Cisco IOS In-Service Software Upgrade Process
About ISSU
Figure 5-1 Cisco NSF with SSO Network Deployment: Service Provider Networks
Additional levels of availability may be gained by deploying Cisco NSF with SSO at other points in the
network where a single point of failure exists. Figure 5-2 illustrates an optional deployment strategy that
applies Cisco NSF with SSO at the enterprise network access layer. In this example, each access point
in the enterprise network represents another single point of failure in the network design. In the event of
a switchover or a planned software upgrade, enterprise customer sessions continue uninterrupted
through the network in this example.
Service
provider
core
layer
Service provider
distribution
layer
Service
provider
access layer
Cisco NSF with SSO
features may provide
some benefit, but usually
not required
Good position for
NSF-aware
routers
Primary deployment
position for Cisco NSF
with SSO capable-routers
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Customers