MTNL has failed to modernize itself and is a dying elephant. Staff, cabling and equipment are old and have failed to update with the technology. It has vast resources in the form of priceless land holdings. The landholding and such assetts could have been used to modernise and change to fiber optics for trouble free connectivity. Now all services are very poor.
------- Edited on 2018-07-03 -------
Airtel does not provide speed promised as per the plans. recently I was given a internet connection with promise of 100 Mbps. Where as their staff told me that it is not possible, it will be less than 25Mbps. Their rates are also on higher side. Their service is good, may be because it has been outsourced.