I have been using MTNL Broadband since October 2015 only because no other broadband service is available in my area, I have 4mbps plan, the speed is as advertised, for almost 10 months my connection used to disconnect every 2 minutes. I used to make complaints and it used to stay connected for 2 hours after someone does something at MTNL office.
Now I made them visit my area and fix the line. After line man attended my complaint I am getting stable internet now, it disconnects only once in 3 days. If you are on MTNL and suffering from frequent disconnects make your line man visit and fix your line by booking a complaint "Noise problem" under landline fault.
Very happy with the connection