Hello! At this moment, the trackers work on the native application, when setting them up, the server IP and the port are required. At the company level, a server was created for the gpsTRACCAR monitoring application, which requires a fixed IP. The 4G router, from another manufacturer, was configured with fixed APN and IP, in bridge mode. The problem for the GPS on the cars, only those that communicate with the servers via the NMEA protocol, is that the router, configured in this way, does not retransmits the received data to the Traccar server. The manager of the opensourceTraccar application informs us that not all routers retransmit or allow the transmission of data, in the NMEA protocol, from the GPS tracker to the server or do not retransmit the device ID, the only one necessary to register the tracker on server. Other opensource applications, for the NMEA protocol, allow the installation of a supplement and the protocol is received. Thank you!