BSNL broad band connection in ubuntu

Here are the things to do to get DataOne working on Linux:

1. Plug in a LAN card and make sure that the required driver
   is present in the kernel, either compiled-in or loaded as a module.
2. Connect the router to the ethernet card.
3. Assign an IP address for the ethernet card; the router has a
   fixed interface address of 192.168.1.1, so you can use 192.9.168.2
   for your ethernet interface. Just do `ifconfig eth0 192.168.1.2′.
4. Set up the route - just do `route add default gw 192.168.1.1′.
5. Enter the address of some DNS servers in /etc/resolv.conf (
   eg: 61.1.96.69, 61.1.96.71)
6. Try doing a `ping www.google.co.in’. If it works, great! If
   not, check whether it is some problem with the DNS settings by
   pinging a machine with the I/P address rather than the name. If
   that too doesn’t work, you will have to do some configuration on
   the router.
7. You can access the router via a browser - just enter the
   I/P address 192.168.1.1. You basically have to set the connection
   type to `PPPoE’; on my MT880 box, this comes under `WAN Settings’.
   You will then have to enter your user name and password (username is
   of the form xyz@dataone) and reset the router. It will take 2-3
   minutes for the box to come up again - when it comes up, it will
   `automagically’ talk with the box at the exchange (via PPP?) and
   will be assigned a proper IP address. You need not bother about this
   address as you always see the router at a fixed address of 192.168.1.1.
8. Try pinging google.com again - it should work! You are now on
   DataOne!

I am getting connection speeds of about 190Kbps consistently; that
should be OK, given the distance. Some of my students who are staying
near the telephone exchange report that they are even getting speeds
greater than the promised 256Kbps!

source:-http://pramode.net/2005/07/30/782/

See:-

http://www.ubuntu-in.org/wiki/Broadband_Howto