If you are also one among affected by “Limited Connectivity ” problems of BSNL broadband, this is a fix that worked for me today !!

Go to command prompt and check if u are able to ping to http://www.google.com , if yes then try resetting the router,else go to your router settings (for me its 192.168.1.1) username : admin pass: admin. Now select ” WAN”  from the left pane select the first option and select edit, now u ll go through  a series of menus under the one that has a username password check whether its username “ka44********”,this for chennai i dunno for the rest of the cities , this is nothing but ur username password that was given to u during installation of the broadband connection , now password would be “password” (i hope so), see if the service name is “dataone” now save the settings and reboot ur router ,your internet connection must now be working fine 🙂