Cisco Catalyst 4500 Series Software Configuration Manual page 403

Chapter 8 Configuring the Cisco IOS XE In Service Software Upgrade Process
Figure 8-1
Service
provider
core
layer
Service provider
distribution
layer
Service
provider
access layer
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.
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 would continue uninterrupted
through the network in this example.
Cisco NSF with SSO Network Deployment: Service Provider Networks
Customers
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
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
Figure 8-2 illustrates an optional deployment strategy that
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