When the active-sim command is set to auto, the operator can configure the parameters that will cause an automatic failover to occur. The parameters that serve as criteria for automatic failover are:
the cellular port operational state
the operational state of all BGP sessions configured on the node
the RSSI value
These parameters are configured per SIM and can be different for each SIM. As well, any combination of parameters can be configured for each SIM.
An automatic failover occurs when the conditions are met for any of the configured parameters on the currently active SIM.
Automatic failover between SIMs can continue indefinitely until either the recovery timer expires, which will reboot the entire system and bring up a cellular port based on the preferred SIM, or the operator manually intervenes to halt automatic failover by configuring a specific SIM as the active SIM.
When the operational state of BGP sessions is the failover criterion for a specified SIM and established BGP sessions are operationally up on a WLAN or Ethernet interface, the node will not perform a SIM switchover until all BGP sessions are down. When BGP is required to monitor the state of the cellular interface, ensure that only the cellular interface can establish BGP sessions. When BGP sessions are required over WLAN or Ethernet, use the operational state of the port as the failover criterion in order to ensure automatic SIM failover.