Hi,
again I’m writing because 2G/3G communication is not working as intended. Lets forget about all the USB and miciPCI-e 2G/3G problems that were already heavily documented but not solved. Because of this fact I started to test 2G serial modems. I put together a RB411 with a serial port and disabled the console on serial0. The router connected in an instant and was working for 2 weeks until this night when it disconnected. I have one more router (RB411UAHR) on-site, that uses 3G and is connected to the test router, so I was able to access it. The thing I saw was, I wasn’t able to communicate with the modem via serial port. I couldn’t enter anything (/system serial-terminal serial0) as if the modem was inaccessible on serial0. The modem uses standard AT commands. I tried to reboot the router to no effect. So I drove to the site and changed the test router and connected it back to the serial modem… and it worked. Be advised I did not power cycle the serial modem, only reconnect it to the other Mikrotik.
serial0:
baud: 115200
parity: none
data bits: 8
stop bit: 1
flow control: none
I am quite confident now, that the problem is in Mikrotik and not compatibily with 3rd pary hardware, because this modem uses standard AT commands and doesn’t need any drivers.
I really need help with this one, because I can understand that if you have a 3G router at home it is no problem to reset it once a week, but once you use 300+ routers scattered around EU, then you see problems and patterns emerging.