BSNL Dataone Broadband

In the BSNL Dataone Broadband bill if you see details like GU, FU, NU don't scatch your head.
What they mean is
GU - Gross Usage
The total megabytes you have used for the month
FU - Free Usage
The total amount of megabytes for which you will not be charged according to your plan. For example for 250 Plan you can use 400MB for free
NU - Net Usage
This is Gross Usage - Free Usage

If you have any doubts regarding this billed usage, you can use the online usage check site provided by dataone here http://www.sancharnet.in/dataoneredirect.htm(Note, this site works only from Internet Explorer)