How It Works?


I read about Asterisk a while ago and remembered it the other day when I realised I was going to be needing some sort of telephone system for a company I’m looking to set up.

For a variety of reasons it would not be possible for me to connect the phone system to a land line and I would have to rely on VOIP which I believe Asterisk supports, but I just don’t know how that works!

I have found a number of sites offering to sell 0800 numbers, but if I get such a number can I then connect it to Asterisk and how does that work.

Also, how many connections can be made to this system. If someone is already calling my VOIP number will it still allow other people to queue or would that require multiple lines?

If someone could help me understand the basics of how it works I might be able to make more sense of the user documentation!

Thanks a lot!


An itsp (internet telephony service provider) can give you a 800 number and you can use it with * if the itsp supports at least one of the voip protocols supported by *: sip, iax2 or h323; also there is no problem with multiple concurrent calls, you just need to have an internet connection with enough bandwidth, I think all itsps support concurrent calls per number, there are no technical problems about and the itsp I’m using supports this.

Hope it helps.


Marco Bruni

Thanks a lot, would I be right to presume the downloadable O’Reilly book includes details on how to configure Asterisk with these technologies?

I started reading it but all it seemed to cover was using it with a standard telephone system which was rather confusing!

In this book there is few about a connection to an itsp, by the way you should read it because explains quite well the * dial plan, which is very
important to understand.
To use an itsp just configure a friend/peer in sip.conf and create/modify the dial plan in extensions.conf to route in/out calls.


Marco Bruni