SIM-switch

SIM-switching can be configured by data plan, disconnect settings, signal strength, coupled with switch back by time or by timer. All these options are under the “Auto switch” setting.

FortiExtender comes with two SIM-card slots per modem, with the first one (i.e., sim1) being the default. SIM-switch works only when you have two SIM cards installed on a FortiExtender device with the feature enabled on it. SIM-switch is disabled by default, you can enable it using the following commands:

config auto-switch

set by-disconnect disable

set by-signal disable

set by-data-plan disable

set switch-back

end

With SIM-switch enabled, FortiExtender automatically switches to sim2 to maintain the current LTE connection when any of the following situations occurs:

• An Internet session gets disconnected. By default, FortiExtender automatically switches to sim2 if sim1 gets disconnected for three times within 600 seconds. You can change the values using the following commands:

config lte setting modem1

config auto-switch

set by-disconnect enable /*enable the switch by disconnect feature*/

set disconnect-threshold <3> /*Number of disconnects for sim-switch*/

set disconnect-period <600> /*Disconnect evaluation period for simswitch*/

end

end

• Data usage has exceeded the set limit of your data plan and overage is disabled. By default, overage is disabled. SIM-switch does not occur if overage is enabled. You can use the following commands to set the capacity of your data plan and enable or disable overage:

config lte setting modem1

config auto-switch

set by-signal enable /*enable the switch by signal feature*/

set by-data-plan enable /*enable the switch by data usage feature*/

end

end

config lte plan

edit <plan>

set capacity <data plan in MB>

set billing-date <billing date>

set overage {enable | disable}

set signal-threshold <-100> /*RSSI to be evaluated*/

set signal-period <600> /*Signal evaluation time in seconds*/

next

• The relative signal (RSSI value) stays lower than the specified value for a major part of the time period defined. By default, the RSSI value is -100, and the time period is 600 seconds. This means that SIM-switch occurs if the RSSI value stays below -100 for more than 300 seconds.

RSSI Values and LED State

RSSI	LED-1	LED-2	LED-3	LED-4
0, or N/A, or 'rssi<=-100'	OFF	OFF	OFF	OFF
-90~-81	ON	OFF	OFF	OFF
-80~-71	ON	ON	OFF	OFF
-70~-61	ON	ON	ON	OFF
rssi>=-60	ON	ON	ON	ON

SIM-switch is a feature in data plan configuration which can be configured from FortiEdge Cloud or locally from the FortiExtender GUI. All the aforementioned parameters can be configured from the FortiExtender CLI.