Good ISP in Kolkata for stable ping, minimum downtime?

Hello

I'm Looking for a good ISP mainly for online multiplayer, streaming and video/voice chat. Important stuff I'm looking for;

1. Should have constant ping/jitter value throughout the day,month and year.
2. No mini-downtimes (5-10 min) throughout the day which suddenly kicks you out of games/chat.
3. No live IP/Port block issues (Doesn't let you log in to certain services like Playstation network, Uplay etc.)

Basically an ISP that has a solid score in pingtest.net ie; not just speed but network quality. Don't care about cost-speed value.

Any suggestion is greatly appreciated. Help out a fellow gamer!