This design guide evaluates Cisco VPN product performance in scalable and resilient site-to-site VPN
topologies, using Cisco VPN routers running Cisco IOS Software, with IPsec as the tunneling method.
The concepts presented can also be applied to other Cisco products that do not run Cisco IOS software.
This design guide begins with an overview, followed by design recommendations and product selection
and performance information. Finally, partial configuration examples are presented.
The chart in Figure 1shows the IPsec VPN WAN architecture documentation, which is divided into
multiple design guides based on the technologies used. Each technology uses IPsec as the underlying