Asterisk and international calls

Hey guys,
I had setup an Asterisk system couple of years ago. I don’t remember much about it now, but I was wondering if it is possible for me to setup an Asterisk system at my apartment, and use it to make international calls? The calls are not business related (they are personal). If it is possible what will I need to set it up? Will I need asterisk setup at the other end as well?


okay you need 5 white candles, 2 red candles, 2 liters of cows blood (fresh) and a live chicken… do you know how to draw a pentagram?

just kidding. it really depends on what you want to do.

If you want to make int’l calls to normal phones, you need a voip carrier. broadvoice and viatalk and quantumvoice are good choices. this will cost you about $20/mo. You can also get a prepay carrier like voicepulse connect and they will only charge you per-minute.

If you can install some stuff on the other end (IE if this is for relatives or family) it becomes easier and cheaper. start by buying them an IP phone- grandstream bt200 is a good choice.
At that point you can either register the phone to your server directly, in which case you can dial each other by extension and not much else; or you can get two accounts on a free VoIP network like FWD (free world dialup) or SIPphone. If you do that, register both * and their phone to that network, and you can then call each other.

hope that helps!

Hey IronHelix,
Yes they are family. I already have a calling card system but my monthly bill is couple of hundred buck. So I was wondering to cut down the cost using asterisk. What you said about the buying the IP phone and registering will work as follows?

  • setup up asterisk on my end.

  • get 2 ip phones. (one here, one there)

  • have the international ip-phone connected to broadband and then register that IP address to my system here and assign a extension.

  • then all I have to do is pick up the phone here and call the extension.

Do I still need a voip carrier?


if you do it that way with the * server, you are the voip carrier and no services are needed.

You could also set that up so you (but not them) can use the IP phones to dial out on your PSTN line or VoIP carrier…

also to clarify- a provider like sipphone or FWD is free, but you can only dial other users of free SIP networks (although they sometimes peer with pstn-connected SIP networks so you can call them too)

Ok, so I will setup up the Asterisk server on my end. One more question, is it ok if their phone and my phone are behind the router? My asterisk server will be behind the SmoothWall. And I would like to setup the phone over there behind a router so they can use the computer as well.

yes that is acceptable. it greatly helps if you have a static ip.

forward udp ports 5060 and whatever is defined in rtp.conf through your router. set externip= and localnet= in sip.conf. If you have a dynamic ip you can set externip= to be a dynamic dns host and there as i recall is an option to re-query it every now and then.

for your IP phone (presumably also behind the NAT?) turn off STUN and set nat=no

for their IP phone use STUN (free servers are or as i recall) and possibly set nat=yes. If you do this you shouldn’t need to forward ports. You might also want to set qualify=yes or set the maxexpirey to be a low number (say 120) so the NAT mapping stays alive.

good luck!

If I can do this, then I am assuming that I can set it up such that, if they call the extension it gets forwarded to my cell phone, and I can call the asterisk server from my cell phone and it will be forwarded to them.

Although I am not sure how it is possible for me to call the asterisk server from my cell, I am guess that will require me to register another phone number, or can I use my existing number? By I currently have Comcast’s VoIP service. I probably should have mentioned that earlier, not sure if that will complicate or make thing easier for setup.

first stuff- sure.

you can do-
exten => 1234,1,Dial(SIP/yourphone&SIP/provider/yourcell#,20)
so they can dial 1234 to get you locally or on your cell, without giving them the ability to randomly dial out.

as far as the rest of it (you dial in) that can be done with DISA().

comcast voip will not be perfect but it may be possible. you will need an FXO port and an analog line to hook up to it. Then Asterisk will probably become your answering machine, because it has to pick up the line- * won’t ‘listen’ when other devices are picking up, it expects to be the only thing dealing with the line.