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A dual SIM router or tracker holds two SIM cards – typically from different network operators. If the primary SIM loses signal or hits a data cap, the device switches to the secondary automatically. A remote monitoring site stays connected even when one operator has an outage in that area.
The quality of failover implementation matters as much as having two SIMs. Good implementations keep the idle SIM registered on the network but data-inactive, so switching is near-instant rather than waiting for a full re-registration.
- Switch triggers: weak signal, failed ping test, data cap hit, or network connection error
- Idle SIM protection – secondary SIM stays registered for fast activation
- Failback settings – return to primary automatically after it recovers, or hold on secondary
- Two different operators provide genuine redundancy; two SIMs on the same operator do not