Thanks a lot dear. Actually nothing was happening on mobile, no call history or any activity. BT1 & BT2 were also verified. However, trunk idea seems very good. I tried, now it tries to dial the number on mobile. Though it didnt work yet but as you said it could be dial plan thingy. If I dial **81 then my destination number, mobile adds an additional 1 in the beginning. If I dial **8 then number, then I get a fast busy tone as soon as I start dialing number.