Is FreePBX right for me? (I want to call someone in a different country using the internet to save on roaming fees.)


A quick little about me: I’m not technically versed in the PBX world. I know computer basics and I can set up a Raspberry Pi. I’ve tried to gather as much information as possible, but please go easy on me! :slight_smile:

I have a friend in a different country and she has a very bad 3G/4G connection so any calls over data (e.g. Skype or WhatsApp) drop all the time. I wish to be able to call her “locally”, using some sort of device I can maybe make out of a Raspberry Pi.

There’s a business I’m involved in, which operates in the same country where she lives. There’s broadband / LAN connections on the business premises. I’m thinking that I could have a Raspberry Pi connected there with a dongle that has a local SIM card. (“GSM gateway”?)

I’d like to use my internet connection from where I live to call the Raspberry Pi because it would have a stable internet connection as well, then have the Raspberry Pi “call” her over GSM. I think this is called “call termination”, however the closest to this tha I found in an out of the box solution costs almost 300 euros!

I’m not sure what the software would look like, so I stumbled on FreePBX and I’m thinking maybe it can work. Does anyone have experience with trying to achieve what I’m trying to? I’d like to avoid paying for a VoIP provider. If I can make this myself and send it to my friend, I can have someone then install it at the business location including getting the prepaid SIM card for voice.

I’d love any pointers / guides how to do this. Thank you so much.

This drops your traffic back onto the 4G network, so you’re not going to gain much.

Setting up a FreePBX server at the remote and and then using it to avoid tariffs (even if it is for a perfectly reasonable technical reason) might get you in a little more trouble than you might want.

FreePBX is a Back to Back User Agent, so you would set up FreePBX servers “here and there” and then use whatever technology you want to get into the other country’s POTS network, or GSM network (in the case of a GSM Gateway). You can connect the two servers via SIP or IAX2 protocols and pass your traffic back and forth. Note there is a steep learning curve on this part of the process and it isn’t always a straightforward as most new users would like.

We have many people on here that operate using GSM gateways, but FreePBX doesn’t do anything for you when it comes to management - you have to do the configuration and management of the gateway device yourself.

Thank you for the detailed help. I really appreciate that! I have some follow-ups:

1/ You said a GSM gateway would drop my traffic back onto the 4G network, but to clarify calls over 2G in the country work perfectly fine. It’s the 3G/4G data that is the problem. So wouldn’t I be in the clear? (EDIT: Specifically the Raspberry Pi would be connected to LAN and also have a USB dongle with a SIM card connected. Data over LAN, call over GSM.)

2/ Can I not use a “softphone” app on my iPhone to call the device using SIP and have it configured so it calls the number I enter in the other country? Thus avoiding having to have two servers?

3/ If this stuff is more involved for what I need, do you have pointers what would be simpler for someone like me? Thank you!

  1. I’m not sure a GSM gateway is going to give you access to the data network, and most 2G data networks are woefully inadequate for your needs for what I think you’re describing. It’s just my opinion, though, you won’t know until you try.

  2. You can use a softphone app on the iPhone to talk SIP to anywhere in the world - you don’t need a remote machine for that. You can set up a server in your local office and she can connect via a “local” extension from anywhere in the world that has Internet. There are going to be security concerns that you’ll need to address (UCP or not?, can you predict where her phone will be?, etc.) This approach save you a lot of trouble, but if the network is spotty, even with ALaw you might not get enough bandwidth to make this a workable solution.

  3. The simplest way to deal with this is to use a SIP phone app and connect it to a FreePBX server somewhere in the world and both of you use that. With or without GSM is up to you - but I know we’ve answered a lot of questions about GSM gateways and getting them to work reliably. If the underlying provider’s network is not reliable, your GSM gateway isn’t going to fix that.

Unless one of you is in a place where VoIP is illegal, please tell us what country you are in and what country your friend is in. There may be inexpensive numbers available in her country that would ring directly to you, without any special hardware. Or, VoIP calls to her mobile may be inexpensive, perhaps less than the prepaid mobile would cost.

Also, please post: Estimated monthly minutes usage? What would the proposed prepaid mobile cost per month? If not ‘unlimited’, cost per minute? If this is a country where incoming calls to a mobile are free, does she have an ‘unlimited talk’ or ‘unlimited calling to the same carrier’ plan so she could call you for free? Does she have a landline? Does she have wired internet at home?

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There are several services that will provide you with a DID/DDI in differnet countries, Your friend can call that number and not have to worry about her last mile data connection deficiencies, you can send an SMS to her to have her call that number and ( all this as @Stewart1 suggested )

You should check the cost of calling into a Cell Phone , in many (if not most countries) you will find out very quickly why SMS took off so bigly. So likely her calling a landline will be very much more economical.

Thank you once more for the answers. My follow ups:

1/ think we’re talking about different things, could it be? My friend lives in East Africa and I’m involved in a business there. In that business location there’s broadband that I can use and that’s the data connection I’d be using to communicate to the device (be it a Raspberry Pi or similar, using a simple LAN cable). What I need the SIM card to do, connected via a dongle, is to just provide the 2G voice communication. Am I wrong to assume this is how it could work?

2/ I’m glad to hear a softphone is all I need on my end. What I need on her end is that she uses 2G voice on her phone to call the number (or receive a call from me), but the device that has the local SIM card installed would then initiate a connection to me over the internet, using the broadband available in the business location.

3/ Thank you, I think FreePBX then could be something I use!

Hello and thanks for taking the time to respond.

I’m in Europe and she’s in East Africa. I’ve figured that in the countries where we live, there’s not a problem setting up something like this for our own use. It’s a different matter if I sold this as a service to somebody else, but this is just for my use.

There are no inexpensive numbers available in her country. I’ve checked all the possible international SIM providers, calling card providers, even Skype doesn’t support her location (Skype to Phone), and as I have mentioned the data connection to her mobile phone is spotty at best, so I’m specifically trying to reach her through 2G voice, but making it so it’s a “local” call from her perspective and whatever device I have installed over there is then connected to a stable broadband internet connection and that would connect to me in Europe.

I don’t know how to answer, I’m not sure myself. Could be 1 hour (60 minutes) weekly. Sometimes maybe more. With a prepaid SIM card if there’s a way I can access the USSD codes, I can just top up as needed (and this is a part that I can easily figure out, such as sending her money over PayPal and then she “texts” me the money using Mobile Money in her country to the phone number associated with the gateway devie).

She has no landline and no wired internet at home, that’s the problem. In her location she only has 3G or 4G if she’s lucky, but the connection isn’t stable. So it works for surfing the internet and maybe watching YouTube videos, but the connection is intermittent and thus breaks every single calling app we’ve tried that uses data.

Thank you!

Thanks for the response!

I had to look up DID/DDI. That’s not a service provided there in her country. Again, 2G voice works wonderfully. I just need 2G voice -> some device -> internet -> my phone. Then we eliminate the issue of data connection deficiencies at her end. My understanding is that “some device” could be a GSM gateway. Am I correct here?

Calling her directly is extremely expensive, something I want to avoid. A prepaid SIM at her location and the occasional top ups + the cost of a device I can configure myself + shared cost of the broadband connection at the business site equals enormous savings compared to any service provider, VoIP provider, calling directly, using an international SIM provider, or anything else similar. I’ve exhausted all options.

She has no landline access either. We’re talking not precisely rural East Africa, but similar conditions.

Does the business have an analog landline, or a PBX with a spare analog extension port? If so, using a box such as

and a free account such as
you could set it up so that when she calls the business, the OBi would recognize her caller ID (other callers would be ignored) and send the call to your extension, where you would have a softphone, SIP app or hardware SIP device registered.

No PBX required and no monthly or per-minute charges at all.

Otherwise, perhaps

would do the trick.

Hello! Thanks for helping out. Unfortunately there’s no landline in the business location either and no PBX. Only broadband internet.

Oops, I had edited my previous post but after your response. Will the GoIP work in your application?

I think you’re on to something! Looks like the GoIP-1 is exactly what I’m trying to make myself.

I’m having such a difficult time finding this particular device from a reputable European seller. All websites look very sketchy. I’d rather build this myself with a Raspberry Pi if that’s possible.

Can I do that? Would FreePBX help me in making my own “GoIP”?

There are two ways to get a GSM trunk on Asterisk.

Chan_dongle uses a USB GSM modem. It’s fussy about particular models and often requires updating firmware or issuing special setup commands. See

The alternative is chan_mobile, which uses Bluetooth to communicate with a mobile phone. This is much simpler and on a Pi 3 or 4, Bluetooth is built in so an old phone is all you need. However, if something goes wrong with the phone there is no easy way for you to reboot it remotely, so you’d have to wait for someone at the site to help you. See

If the business has a static or de facto static IP address and you administrative access to their router, you can register your SIP app or device directly to the Pi. You can still do this with a dynamic IP by using a dynamic DNS service, but that doesn’t work well if the address changes frequently.

Perfect! You’re an amazing person. My googling skills turned me to similar looking guides, but they ended up being for other things. This is exactly what I need. I’ll look into it and get to work.

re: IP, it’s really not a hassle for me to periodically update the IP manually myself, it could be a dynamic DNS or something as long as it works, these would be small scale issues to iron out :slight_smile:

THANK YOU so much!

No doubt I’m missing something here, but I think you are as well. With VoIP, which is what you’d ordinarily be using with FreePBX, the distinction you’re making between voice and data really doesn’t exist–the voice signal is digitized on one end, transferred over a data connection, and turned back into a voice signal on the other end. If the only goal is for you to be able to call her and vice versa, and both of you will be at locations with broadband Internet, all you need is:

  • An IP phone for you
  • An IP phone for her
  • A PBX
  • and the ability for both your phone and her phone to connect to that PBX.

The IP phones can be actual hardware IP phones (those I’ve seen start at about US$60 each), they can be ATAs like the OBI device posted up-thread (plug in a regular analog phone and make VoIP calls), or they can be a soft phone, software running on your PC and/or your smart phone. If both you and she have smart phones, this can be completely free.

That leaves the PBX, and that’s where FreePBX can come into play. You’d install FreePBX, or another PBX software package (and it looks like 3CX will run free for a year in a Google/AWS/Azure environment) with a cloud provider. I’ve used for some of my cloud work, and been happy with their service and prices. A VPS that would be more than adequate for your needs starts at 3,99 EUR/mo. Install FreePBX on that, and log both your phone and hers into it as extensions. You don’t need DIDs, you don’t need trunking, you don’t need any other SIP service. The only recurring cost is for the VPS.

I haven’t used them personally, but I’ve seen crowncloud recommended as well. They have a turnkey PBX installation for $25/yr, and they also have servers in .de and .nl (Contabo is in .de). This would cost less than Contabo, and the installation would be pretty much done for you. But again, I haven’t used them so can’t offer a personal recommendation.

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