•  wvdial -It is a PPP dialer with built-in intelligence (Previous distros of Ubuntu used to have this packaged). To get this program do an apt-get

$dmesg (don’t bother about the elaborate o/p after executing this command)
3.Now, execute the next command and look for ZTE and the corresponding device id and vendor id.
$cat /proc/bus/usb/devices
I found these for my modem(it’s the same for most ZTE mg880) -vendor id:0x19d2; product id: 0xfffd
4. Next, perform a modprobe to make the kernel aware of the modem
$sudo modprobe usbserial vendor=0x19d2 product=0xfffd
5. After modprobe, run a dmesg again,and if  the modem has been detected there will be a message saying that the USB core driver has been registered
6.Next, comes configuring the wvdial. To do this, run the following command
$sudo wvdialconf
To detect the modem wvdial will scan through all the serial ports, check the baud rates and give a message with the optimum baud rate and the port on which modem has been detected.
7. Now comes editing the wvdial config. 
$sudo gedit /etc/wvdial.conf
Edit the contents to:


[Dialer zte]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = Analog Modem
Phone = #777
Username =
Password =
#username and password is your modem’s phone number
ISDN = 0
SetVolume = 0
FlowControl = Hardware (CRTSCTS)
Modem = /dev/ttyUSB0
Dial Command = ATDT
Baud = 9600
#Baud rate might vary
Stupid Mode = 1