The guest anchor controller is usually located in an unsecured network area, often called the demilitarized zone (DMZ). Other internal WLAN controllers from where the traffic originates are located in the enterprise LAN. An EoIP tunnel is established between the internal WLAN controllers and the guest anchor controller in order to ensure path isolation of guest traffic from enterprise data traffic. Path isolation is a critical security management feature for guest access. It ensures that security and quality of service (QoS) policies can be separate, and are differentiated between guest traffic and corporate or internal traffic.
An important feature of the Cisco Unified Wireless Network architecture is the ability to use an EoIP tunnel to statically map one or more provisioned WLANs (that is, SSIDs) to a specific guest anchor controller within the network. All traffic-both to and from a mapped WLAN-traverses a static EoIP tunnel that is established between a remote controller and the guest anchor controller.
Using this technique, all associated guest traffic can be transported transparently across the enterprise network to a guest anchor controller that resides in the unsecured network area.