186 | Uplink Configuration Dell PowerConnect W-Series Instant Access Point 6.1.3.4-3.1.0.0 | User GuideProvisioning a 3G/4G Switch NetworkTo provision a 3G/4G switch network, provide the driver type for the 3G modem in the USB type text box andthe driver type for 4G modem in the 4G USB type text box and click OK.Figure 157 3G/4G Switch NetworkUplink SwitchoverThe default priority for uplink switchover is Ethernet and then 3G/4G. The IAP has the ability to switch to thelower priority uplink if the current uplink is down.Uplink Switching based on VPN StatusInstant supports switching uplinks based on the VPN status when deploying mixed uplinks (Eth0, 3G/4G). WhenVPN is used with multiple backhaul options, the IAP switches to an uplink connection based on the VPNconnection status instead of only using Eth0, the physical backhaul link. The behavior of the uplink switching isdescribed as follows: If the current uplink is Eth0, this uplink is used until the VPN connection is down. When the VPNconnection is down at which point a different uplink (3G) is selected. If the current uplink is 3G, and Eth0 has a physical link, the IAP periodically suspends user traffic to try andconnect to the VPN on the Eth0. If the IAP succeeds, then the IAP switches to Eth0. If the IAP does notsucceed, then the IAP restores the VPN connection to the current uplink.Uplink PreemptionWith this feature, the IAP tries to get a higher priority link every ten minutes even if the current uplink is up. Thisdoes not affect the current uplink connection. If the higher uplink is usable the IAP switches over to that uplink.Pre-emption is enabled by default and the user can disable it by configuration.Uplink PreferenceSelect the type of uplink from the uplink preference drop-down list under Management. To use a 3G/4G uplink,select 3G/4G from the Uplink preference drop-down list.NOTE: IAP reboot is not required for uplink swtichover process.NOTE: If VPN is configured, IAP monitors the VPN status, once VPN status is down for 3 minutes, the uplink switches over (if lowpriority uplink is detected, and the uplink preference is none).NOTE: This feature is automatically enabled when a VPN is configured in the IAP.
