Thank you lazimpat for the recommendation. I tried this www.tel3call.com and I like it. This calling system is really nice. Don't have any hassle of buying card and call to nepal is very clear. Price is reasonable of 19 cents per min. It can be used pinless if you are calling from registered telephone number or enter your account number / pin code if you are calling from non-registered phone number. I think this is one of the best calling system I used to call Nepal.