Basic question: Path

Hi everybody!
Got a basic question:

Let’s say that I’m calling from my office using sip phone in Toronto to an analog phone in Jamaica.

Behind the scenes:
My sip phone connects to an Asterisk box in Calgary(IP) which connects to a PSTN.
In this scenario, to make it cheaper/logic, the asterisk box in Calgary should send the call to another VOIP server in Jamaica, instead of using PSTN.This server in Jamaica should use local call(PSTN) to the destination.

My question is:
How does Asterisk in Calgary know that he needs to send the call to a Jamaican territory? Who determines the path? How does asterisk know the nearest voip server to the destination?


It’s not your Asterisk in Calgary that knows that. It’s your VoIP provider. You design the dial plan so that Asterisk sends long distance calls to a VoIP provider. The provider then accepts your call and routes it as necessary.

Does that make sense?

You don’t mention the key component of the VoIP carrier in your question. You need one. If you haven’t contracted with a carrier than you’d need to do that. Otherwise you would need to have a an existing relationship with a VoIP server in Jamaica, which from your questions sounds like you don’t have :wink:.

Just for argument’s sake, if you DID have an Asterisk box in Jamaica, then you would connect your Asterisk server to Jamaica via an IAX trunk and create a dialplan that would send calls along this trunk.


Thanks for your reply.

It makes sense. VOIP carrier? i don’t know what you mean.
Can you explain what Voip carrier is?


Read this book: … +Telephony

You can download it for free.

Also read through the documentation at