hi, this configuration works for me, i hope would be useful.
*19d2:0031*) echo "ZTE MF110 (Movistar) detected. Attempting mode switch"
uci delete network.wan2
uci set network.wan2=interface
uci set network.wan2.ifname=ppp0
uci set network.wan2.proto=3g
uci set network.wan2.service=umts
uci set network.wan2.device=/dev/ttyUSB2
uci set network.wan2.apn=internet.movistar.mx
uci set network.wan2.username=movistar
uci set network.wan2.password=movistar
uci set network.wan2.defaultroute=1
uci commit network
usb_modeswitch -v 19d2 -p 0031
sleep 10; rmmod usbserial
sleep 3; insmod usbserial vendor=0x19d2 product=0x0031
sleep 5; /etc/init.d/firewall disable; /etc/init.d/firewall stop
logger "3G: firewall stopped"
iptables -t nat -A POSTROUTING -s 172.16.42.0/24 -o 3g-wan2 -j MASQUERADE
iptables -A FORWARD -s 172.16.42.0/24 -o 3g-wan2 -j ACCEPT
iptables -A FORWARD -d 172.16.42.0/24 -m state --state ESTABLISHED,RELATED -i 3g-wan2 -j ACCEPT
