BSNL used to have a usage check portal on one of the private addresses (10.x.x.x/8). That portal is very useful to check the bandwidth usage for connections (like mine) with limited monthly bandwidth usage. For the last few days, the old portal is offline. I found a new portal on BSNL site. Exploring the site at this moment. There are lot of good features around phone billing. However, I am yet to check the internet bandwidth related details. So far so good.