To operate a Nokia Wi-Fi Gateway, a WLAN-GW group must be provisioned. This group contains a list of either Integrated Services Adapters (ISAs) or Extended Services Appliances (ESAs). A mix of both is not supported. The WLAN-GW functionality described in this chapter is executed on these ISAs or ESAs. WLAN-GW tunnels and sessions are automatically load-balanced over ESAs or ISAs to maximize resource usage.
ISAs and ESAs in a WLAN-GW group can be configured for NAT functions also. A WLAN-GW group can be used in any place where a NAT group is expected, but a NAT group cannot be used as a WLAN-GW group.
For resiliency, standby ESAs and ISAs can be provisioned. ISAs can be provisioned in either an IOM resiliency mode or MDA redundancy mode, where one MDA equals one ISA. ESAs can only be configured in MDA redundancy mode, but MDA refers to the ESA VM itself, not the MDA on which the ESA VM is connected.
All descriptions in the remainder of this chapter apply to both ISA and ESA, even when only the terms ISA and MS-ISA are used. Consult the SR OS Release Notes for an overview of which functionality is supported on each platform.
For more information about ISA and ESA, see the 7450 ESS, 7750 SR, and VSR Multiservice Integrated Service Adapter and Extended Services Appliance Guide.