An automatic failover occurs when activity switches from one SIM to the other.
Automatic failover is enabled in a dual SIM deployment when the active-sim command is set to auto. In this case, the operator must select the SIM to use as the primary SIM by setting the preferred-sim value. The node uses the preferred-sim setting to determine which SIM to use for a cellular port after a system reset.
If the operator changes the active-sim value from auto to 1 or from auto to 2 and the active SIM is the same as the new configuration, there is no change to service of the active SIM.
Changing the active-sim setting so that the newly active SIM is different from the currently active SIM is service-affecting. The recovery time after making this change could range from a few seconds to up to a few minutes.
If the operator changes the active SIM from 1 to auto or from 2 to auto, there is no service outage. The system keeps the currently active SIM up and does not perform any switchover.
When active-sim is set to auto, the operator can use the tools>perform>mda>cellular>force-sim-switch command to manually force a SIM switch.
The auto parameter can be set if there is only one SIM installed in the system; however, the system keeps the currently active SIM up and does not perform any switchover.