This is a simple guide for connecting to internet for Ubuntu for BSNL DataOne users.
Make sure you have a lan(ethernet card). All my efforts to find a solution for usb modem have failed. Better buy a lan card, costs only 200 bucks.
Step 1: Make sure all connections are intact and power, link and lan lights are on in your modem.
Step 2: Hit Alt+F2. Type network-admin. Enter your password if you are prmopted for.
Step 3: Select Wired Connection. Then Disable roaming mode in the check box.
Step 4: Select Static IP in the drop down.
Step 5: Use the following addresses
IP adderess : 192.168.1.100
Subnet Mask : 255.255.255.0
Gateway : 192.168.1.1
Step 6: Select the DNS tab. Enter the following OPEN DNS.
Now you are done. Open Firefox and test your internet. Enjoy.