1. They, for all purposes, do not have customer support:
There is a number (1800-424-1600) but when there are problems in the line, nobody picks it up.
In the rare cases when somebody does pickup and answer, they can never solve any problem. They will just take the complaint and give you a number.
The complaints are never attended; they are silently closed.
2. The connection is very erratic; it goes down without reason and without any support to turn to, it gets very frustrating very soon. In short BSNL DataOne suffers from serious reliability issues
3. BSNL connectivity frequently goes down; so at least you can expect repaid service availability 24/7. Unfortunately on weekends no repairs are done. So if the connection is down during the weekend, then you have no option but to wait till Monday noon before some action is taken.
BSNL doesn’t get the concept of 24/7 broadband connectivity. It expects people to feel that broadband is a luxury and be happy with whatever scrap (crap?) BSNL throws at him.
4. BSNL installation staff are clueless about variations of Operating Systems and environments. Beyond their inane script they are totally clueless and lost. Even guiding them doesn’t help. You are on your own.
5. BSNL offers brain-dead plans like 2Mbps connection with only 1 GB data (download + upload) limit. Subsequent data is charged at 23$ / GB (.90 Rs / MB).