I see, then you can for sure change the port for LAN to WAN no problems based on your usecase.
We have a tutorial here for standard devices https://wiki.teltonika-networks.com/view/LAN_as_WAN_RutOS but I think it should work for TRB140 as well.
There is also this extra tutorial written for TRB2 which you might find usefull:
Attaching few pictures for you how to configure WAN Failover on TRB2. Steps would be:
- Enable HTTP and SSH access to your TRB2 device (for testing purposes, if you would need to connect to device's SSH)
- Insert SIM card in the device and enter APN if necessary. Make sure that mobile connection is working.
- Arrange remote access to the device, either through Public Mobile IP address (if Public IP is acquired) or through RMS (for that, standard mobile connection will be enough. Register your device to RMS and wait for it to connect)
- Connect to device remotely, since local access will stop working after performing below steps.
- Switch device to "Advanced" configuration mode by pressing "Mode: Basic" button in top right corner
- From "Network -> interfaces" menu create new interface with any desired name.
- Configure newly created interface according to your needs. In this example DHCP protocol is used, but you can also use Static IP address.
- From "Network -> interface" menu change "LAN" interface physical settings to "br-lan" interface.
- From "Network -> Failover" menu enable WAN Failover end select desired interfaces.
That is it. Now if you would connect this TRB2 to other other router, from "Network -> interfaces" menu you should see, that its newly created interface became active. From same menu you can arrange interfaces in desired order from TOP to BOTTOM, depending which interface should be considered as primary. For testing purposes, move "Wired WAN" to the TOP.
Once that is done, you would be able to remove/connected Ethernet cable to simulate Wired internet connection downtime. Just take note, that switching between interfaces might interrupt your remote connectivity session. Therefore you might need to connect to device again, just through another interface.
to access the router you will able be able to use the USB port, so no big problems. This includes failover but you will not need that.
To send messages from router to HTTP server: