Reset, accepting default cofiguration, I add only:
/interface ppp-client add apn=internet dial-on-demand=no disabled=no info-channel=2 name=ppp_3G_usb phone=*99***1# port=usb1 /ip dns set allow-remote-requests=yes /ip firewall filter set 3 in-interface=ppp_3G_usb /ip firewall nat set 0 out-interface=ppp_3G_usb /system ntp client set enabled=yes mode=unicast primary-ntp=220.127.116.11 secondary-ntp=18.104.22.168 /system clock set time-zone-name=Europe/Moscow
I've read a lot about modems hanging up, but in my case it's the RB750UP - sometimes runs into continuos reeboots, sometimes freezes completely (my pc LAN interface "identifying" and LAN led on RB750UP off)
I know, I have a poor GSM signal here (-85..-100 dbm), but I tried Huawei e171, e173, Nokia E52, Nokia 6700 Classic - all work for some time, then Mikrotik freezes (why doesn't watchdog reboot it?).
You know, I'm ready for a situation with locked up 3g Modem, but I need stable local network. What can I do with it?