Some console server models (currently ACM5500-Gx, ACM5500–Lx and ACM7000-LMx families) allow you to insert two SIM cards (so you can connect selectively to two carrier networks). The dual SIM failover feature allows the cell modem to selectively failover to the secondary SIM when communications over the primary SIM fails.
Note: Failover between carrier SIM is only possible if both carriers use the same cellular firmware software. Eg It's not possible to failover from ATT to Verizon and vice versa as the US carriers require different cellular firmware software.
To configure dual SIM failover, you need to:
- Choose which of the SIMs is to be the Primary, and the other SIM will be the secondary/failover. Select Internal Cellular Modem panel on the System: Dial menu nominate which slot (Top or Bottom) contains the Primary. Do not select Automatic for Dual SIM failover.
- Check Enable SIM Failover
- Specify how the device will Failback from the failover SIM to the Primary SIM. There are two options
- The 'On Disconnect' failback option will failback to the Primary SIM only after the connection on the failover SIM has failed its ping test
- The 'On Timeout' failback option will failback to the Primary SIM after the connection on the failover SIM has been up for the timeout period. The timeout period is either the default value of 600 seconds if the Failback Timeout field is left empty or the number of seconds you have specified in the Failback Timeout field
- Next you will need to configure each SIM connection with as much information (eg. APN etc) such that it will make a successful connection assuming sufficient signal strength from the cell service provider
- Enter a Failback Test IP address for each SIM. This IP address is used to ping test the status of the cell modem connection and to determine if SIM failover or failback is to take place.
- Configuring DDNS and the Modem Watchdog are optional. DDNS, when configured, will be applied to the cell modem dial out connection regardless of which SIM is currently in use. Dual SIM failover is for dial out connections only
Note: Dual SIM failover still applies to the cell modem interface when the cell modem itself is used as the console server's failover interface. Be aware that when the console server is failing over to the cell modem interface and the primary SIM fails, total time to fail over to the cell modem and then for the cell modem to failover to its secondary SIM can take several minutes - be patient.