A dual-SIM industrial router provides a second cellular path when the primary carrier fails or degrades, but two SIM slots do not create zero downtime. A reliable design also needs health checks, switch and failback rules, VPN recovery, buffering and stable power. Tespro TR Series routers can support unattended sites and carrier redundancy; verify TR-100 behavior by model and firmware.
How failover works
The router can use ping, DNS, server heartbeat or interface status. After a failure threshold it changes SIM; failback follows policy. Thresholds must balance stability and outage time.
VPN and buffering must be tested
Carrier switching can change public IP and routing, so VPN and application sessions may reconnect. Test tunnel recovery, DNS and retry logic, and buffer critical records.
Tespro Dual-SIM Use Cases
Tespro TR Series routers can be evaluated for pump stations, solar sites, transport equipment, distribution cabinets and machine service. Critical sites may use SIMs from different carriers together with wired, Wi-Fi and cellular paths. Record real failover and VPN recovery times instead of checking only that two SIM slots are present.
Selection and RFQ checklist
✓ Different carriers
✓ Health-check targets and thresholds
✓ Failover and failback
✓ VPN reconnection
✓ Antennas and bands
✓ Buffering and power recovery
Frequently asked questions
Q: Which Tespro industrial router can be evaluated for dual-SIM failover?
A: Dual-SIM configurations in the Tespro TR Series can be evaluated, with TR-100 as a representative model to confirm. Check carrier diversity, switching conditions, priority rules, redial time, VPN recovery, and alarms against the model datasheet.
Q: Does dual SIM combine the bandwidth of two mobile connections?
A: Usually no. Dual SIM is commonly used for primary-backup failover rather than link aggregation. Load balancing, simultaneous links, or special routing policies must be verified for the exact model and firmware.
Q: Is it useful to install two SIM cards from the same carrier?
A: It can reduce the risk of a damaged SIM, account issue, or exhausted plan, but it does not protect well against carrier-wide or regional outages. Critical sites normally benefit more from two carriers after on-site signal testing.
Q: Will PLC or VPN sessions be interrupted during SIM failover?
A: A brief interruption is possible because cellular registration, IP assignment, and VPN rebuilding take time. A pilot should measure failover duration and verify automatic reconnection for engineering software, MQTT sessions, and VPN clients.
