I had tried many internet service providers, BSNL, Sify, etc. But service of Airtel Broad band (landline) is best. Though other service provider’s service remain unavailable for many hours to days. Airtel is almost always working, never ever their service was down for more than few hours (that to late in night and service is never down in working hours). I have many times measured bandwidth, it is always according to their claim. Using this service from last four years and satisfied.
If their is any technical problem, it is solved within few hours. Their customer service is very supportive.