通过wvdial完成4G自动拨号上网

先安装wvdial：

sudo apt-get install wvdial

wvdial需要一个拨号配置文件：

/etc/wvdial.conf

移动卡或者电信卡配置文件如下：

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0
Init3 = AT+CGDCONT=1,"IP","3gnet"
Modem Type = Analog Modem
Baud = 9600
New PPPD = yes
Modem = /dev/ttyUSB0
ISDN = 0
Phone = *99#
Password = card
Username = card
Auto DNS = on

联通卡配置文件如下：

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0
Init3 = at+cgdcont=1,"ip","uninet"
Modem Type = Analog Modem
Baud = 9600
New PPPD = yes
Modem = /dev/ttyUSB0
ISDN = 0
Phone = *99#
Password = card
Username = card

保存后退出，后台执行wvdial:

wvdial&