User`s manual
Table Of Contents
- 1. Introduction
- 2. Getting Started
- Powering on the W406-LX
- Connecting the W406-LX to a PC
- Configuring the Ethernet Interface
- USB Port for Expansion
- SD Socket for Storage Expansion
- Setting Up the Wireless Module
- Configuring the SIM Card
- Entering the PIN Code
- Verifying the SIM Card Status
- Enabling or Disabling the PIN Code Authentication
- Changing the PIN Code
- Unlocking the SIM Card
- Connecting to the Internet
- Reconnecting to the Internet
- Disconnecting from the Internet
- Detecting an Internet Connection Error
- Sending and Reading an SMS Message
- Deleting an SMS Message
- Test Program—Developing Hello.c
- 3. Managing Embedded Linux
- 4. Managing Communications
- 5. Development Tool Chains
- 6. Programmer’s Guide
- 7. Software Lock
- A. System Commands

W406-LX User’s Manual Managing Communications
4-22
address ) IPADDR=$f2
;;
netmask ) NETMASK=$f2
;;
broadcast ) BROADCAST=$f2
;;
esac
done
break
fi
done < /etc/network/interfaces
}
# get the ip address of the specified interface
mname=
module_up()
{
oIFS=$IFS
IFS=‘
‘
FOUND=“no”
for LINE in `lsmod`
do
TOK=`echo $LINE | cut -d’ ‘ -f1`
if [ “$TOK” = “$mname” ]; then
FOUND=“yes”;
break;
fi
done
IFS=$oIFS
if [ “$FOUND” = “no” ]; then
modprobe $mname
fi
}
start()
{
ifcfg_vpn
if [ ! \( -d “/dev/net” \) ]; then
mkdir /dev/net
fi
if [ ! \( -r “/dev/net/tun” \) ]; then
# create a device file if there is none
mknod /dev/net/tun c 10 200
fi
# load modules “tun” and “bridge”
mname=tun
module_up
mname=bridge
module_up
# create an ethernet bridge to connect tap devices, internal interface
brctl addbr br0
brctl addif br0 $iface
# the bridge receives data from any port and forwards it to other ports.
i=`expr 0`
while :
do
# generate a tap0 interface on tun
openvpn --mktun --dev tap${i}
# connect tap device to the bridge
brctl addif br0 tap${i}
# null ip address of tap device