Voip Service provider using asterisk!

Hello All,
I am new to Asterisk (I am using linux for quite some time and I have built my own linux desktop from scratch) . I have the following scenario :

I live in Germany and my parents live in India. At the moment when I want to call my parents, I use a Voip service provider account (dialnow.com) to call to my parents who has got normal PSTN telephone.
My question is :
Is it possible to use asterisk to become a voip service provider ? In other words what this Voip service provider is doing right now, I want to do it by myself. To start with I just want to call my parents (i.e. I want to call to any PSTN lines in this world), nothing else.
If this is possible, what hardware I require apart from the computer where I will install the asterisk ?
I have started reading the book (O’Reilly Definitive guide), but I didn’t get the answer.

This is the sort of question where if you need to ask, you probably shouldn’t even be considering it.

You will need, probably in India, an ISDN connection (possibly a high order one) to the PSTN, an ISDN card for each set of 30 channels you want to serve, a PC, and a reliable souce of power, as well as what is needed for internet connectivity.

For this to be cheaper than using the existing service, you will need to generate enough traffic to keep the system busy for most of the day, and you will be in a market which is probably already getting overcrowded.

(Whilst you could use a single analogue line, you would still need to keep it busy for most of the time, and you would have added complications like the likelihood that the called party could hold the line open after the caller hung up.)

Or your parents can buy an IP phone and connect to your Asterisk PBX server via VoIP (assuming they have an internet connection). I think this is the thing you want.

Yes, you can run an Asterisk server that is accessible on the internet only to communicate with the persons that connect to your Asterisk servers. All your “Asterisk friends” need a internet connection and a IP Phone or a softphone.