I don't know why your calls are dropping, but you can use the OBiTalk network to call India.
You should already have a Speed Dial setup to call the India OBi200.
If not setup any Speed Dial like this: pp(510123456)
Change the 510123456 to the OBi number of the OBi200.
Now, just dial the Speed Dial number.
If you get the Auto Attendant, reply "1".
If this happens, we can remove the AA prompt.