To start with we need to install two packages usb-modswitch and usb-modswitch-data.

Open up Terminal,and type the following
$sudo apt-get install -yq usb-modeswitch usb-modeswitch-data

Then we need to edit wvdial.conf file (this is a utility that helps in making modem-based connections to the Internet that is included in Linux distributions),

To edit wvdial.conf, type this in the Terminal

$sudo gedit /etc/wvdial.conf

Type the following in the file opened,be sure to add your phone number
[Modem0]
Modem = /dev/ttyUSB0
Baud = 115200
SetVolume = 0
Dial Command = ATDT
Init1 = ATZ
FlowControl = Hardware (CRTSCTS)
[Dialer netconnect]
Username = your device phone number
Password = password (usually the device phone number)
Phone = #777
Stupid Mode = 1
Inherits = Modem0
Now, close the editor and reboot the system.
To connect to the Internet, type this in the terminal

$sudo wvdial netconnect
If you want to disconnect from the internet, just press CTRL+C.

Read more about usb-modswitch and usb-modswitch-data

Post from:

How to configure Reliance netconnect broadband in linux (Ubuntu 10.04 )

Some times we require to change MAC address (Physical Address of network card).This can be temporarily or permanently. Here is a tutorial which illustrates changing  of MAC address in linux/ubuntu/kubuntu

To change the MAC address temporarily

Open terminal and type

ifconfig eth0 down

This command brings the network down 

Later type the following command.

ifconfig eth0 hw ether Your Mac Address

For example, it will be like

ifconfig eth0 hw ether 001B2F1359C3

Later bring the network up by the following command.

ifconfig eth0 up

Now type

dhclient

This DHCP protocol allows your computer to contact a central server which main- tains a list of IP addresses which will be assigned to you.

Now your connection should be up with a new MAC address

If you still find a problem with connection, Just repeat the process after taking the LAN wire connection

If you want to access internet with the new mac address all the time, it would be difficult to repeat the process every time after starting the system

So we need to edit /etc/init.d/bootmisc.sh

Anything in the file loads after the regular boot process.So we can repeat the temporary process here.

Open terminal and type

sudo gedit /etc/init.d/bootmisc.sh

On the bottom of the page, insert the following piece of code

killall dhclient
killall dhclient3
ifconfig eth0 down
ifconfig eth0 hw ether 001B2F1359C3
ifconfig eth0 up
/sbin/dhclient
/sbin/dhclient3

So putting this in the file will change the MAC address everytime the system starts.

Post from:

How to Change Mac Address in Linux (Ubuntu/Kubuntu)