I've lost 2 days to configure DWR-921 C3 to use SIM connection (WWAN), so I want share with you my steps to work it.
With Iliad SIM card follow this guide
uci set network.wwan=interface uci set network.wwan.proto='wwan' uci set network.wwan.apn='iliad' uci set network.wwan.pincode='<your sim pin code>' #if pincode doesn't exist delete this line uci set network.wwan.auto='0' uci commit network uci set firewall.@zone.network='wan wwan wan6' uci commit firewall
Reboot openwrt. Now if you start wwan with ifup wwan you will be able to navigate.
With Tim SIM card I've used modemmanager. Before use it I've installed this packages:
opkg update opkg install usb-modeswitch kmod-mii kmod-usb-net kmod-usb-wdm kmod-usb-net-qmi-wwan uqmi opkg install modemmanager luci-proto-modemmanager luci-proto-3g luci-proto-ipv6 luci-proto-ncm luci-proto-ppp luci-proto-qmi
Following this guide, I've added this lines to /etc/config/network:
config interface 'TIM' option proto 'modemmanager' option device '/sys/devices/platform/101c0000.ehci/usb1/1-1' option iptype 'ipv4' option apn 'ibox.tim.it' option auth 'none'
and I've add TIM to WAN firewall:
uci set firewall.@zone.network='wan wan6 TIM'
Reboot. Wait 1-2 minute and it should connect. (doesn't always it works -> reboot again)
I hope it works