please help to review my router (RB750GR3) config.
i notice this because my main ISP is down, and i have sierra 3g USB modem, that i usually connect for sending sms but when such incident (main isp down) . i configured this modem for back up internet.
here is the weird thing,
when i change to USB 3G Modem, the router rebooted several time as this photo shown
i’ve attached the export files, is there something wrong with my config that causes the router to reboot several time ?
Thank you rb750gr3-20210125.rsc (78.5 KB)
One possibility is that your 3G modem draws too high current and RB750GR3 is not able to sustain it, quite a few of them come with sort of a Y-cable and one branch is used expressly to pick up extra current from another USB port.
You could try to get a powered USB hub and plug it between router and dongle. This way hub’s power adapter will supply power to dongle.
yeah the modem is not part of the supported list. but i think this sierra 885 is compatible tho, since i saw the setting how to make it works in this forum.
i would love to know what caused the unresponsiveness, but there is no output generated by the watchdog.
could be, but i was opening winbox all the time and watch the curent, temp, memory & cpu when it got hang, there is nothing that suggest sudden voltage drop.
the interface window packet just suddenly stop moving and not long the router rebooted.
If what I wrote is the reason, then you won’t see it coming on the usual health sensors. The thing is that one of two most power-demanding things in wireless modem is radio transmitter (the other is CPU/DSP processing both directions) and radio transmitters can use quite high powers … specially if they are not really power-optimized (which is the case with earlier models for each mobile generation, 3G is no exception) … 3G devices are generally allowed to transmit with 200mW - on the antenna. Given the inefficiency of output stage (power amplifier), actual power draw can be upwards from 1W … and 1W for USB-powered devices is really a lot (USB 2.0 standard specifies max power draw to be 500mA @ 5V = 2,5W). If internal design of a board offering USB port is not smartly done, then excessive power draw over USB port can mean drop of voltage used by other components …
But it’s up to you whether to pursue my suggestion or not, I’m giving it to you for free
I got the powered USB HUB.
but somehow it wouldn’t connect to the 3g connection now.
so i can’t reproduce the restarting event. will try to figure out a way to connect to internet using 3g and will update on the progress
