Problem: Aug 2 00:04:46 OpenWrt daemon.info pppd[9652]: Serial connection established. Aug 2 00:04:46 OpenWrt daemon.info pppd[9652]: Using interface 3g-WAN Aug 2 00:04:46 OpenWrt daemon.notice pppd[9652]: Connect: 3g-WAN <--> /dev/ttyUSB0 Aug 2 00:05:13 OpenWrt daemon.notice pppd[9652]: Modem hangup Aug 2 00:05:13 OpenWrt daemon.notice pppd[9652]: Connection terminated. Aug 2 00:05:14 OpenWrt daemon.info pppd[9652]: Exit. Aug 2 00:05:14 OpenWrt daemon.notice netifd: Interface 'WAN' is now down Solution: config 'interface' 'wan' ... option pppd_options 'debug noipdefault' + SET CORRECT TIMEZONE!