Hi Quectel Team,
We are using the EG25-G modem (Firmware: EG25GGBR07A08M2G_30.204.30.204) in a drone communication setup. The modem is connected via USB to a Raspberry Pi 4B (air end), and we have another EG25-G modem on the ground end connected to a laptop.
SSH to the Raspberry Pi works fine initially, and we use it to access video and telemetry. However, after a few flights (random, not consistent), SSH access fails, even though:
- The modem still responds to ping from the ground end.
- The Raspberry Pi stays powered and active.
- The error appears as connection refused, after we do the SSH.
- The only fix is reflashing the modem firmware, after which it works again — temporarily.
We are using static IPs and the network provider confirms they are public.
Questions:
- Is this a known issue with the current firmware (30.204.30.204)?
- Could this be a NAT or port forwarding issue inside the modem?
- What are the recommended steps to ensure stable long-term TCP access (SSH) without needing firmware refresh?
- Are there AT commands or watchdog solutions we can use to auto-recover?
Any help or suggestions would be greatly appreciated.
Thanks!