Personal callback server redux

joeko2202 · **Personal callback server redux -** 22-01-2009, 15:40

Ok, so people have told me I have too much time on my hands...

I'm working on a project to try to get inexpensive cell phone calling in Europe, and working on my own callback server (using FreeSWITCH, a REST web service, and some software on the phone).

Where I'm hitting a snag is the VoIP provider -> mobile phone. There's two routes I can go, either get a local SIM for each region I'll be in (which raises a question, how "tight" are roaming areas in Europe? For example, if I had an Italian SIM, and rode across the border to Austria, would I find that my costs would increase due to roaming?).

The other option is the international SIMs offered and getting a VoIP termination in Europe somewhere. The question there comes from looking at the comparison chart. I'm assuming the prefixes are all mobile prefixes (e.g. +4236 versus +423), since this impacts my magical low cost routing calculator I've got chugging along.

So, I'm looking for some practical experience in this. I believe the local SIM would be the cheapest route, but also the most inconvienent. The international SIM is easier, but the costs may be a problem. Any thoughts?

stefandim · 22-01-2009, 17:04

You definitely have a lot of possibilities.

First, if you get a local sim in Europe, the incoming calls will be free in the home country, but the standard incoming roaming tarif in EU countries is 0.26 EUR/min. Some providers may provide cheaper incoming rates or even for free, for example, the 3 at home offers.

On the other hand, the international sims offer free incoming in a lot of countries. For your type of scenario, I would select an international sim with an UK number, since they are the cheapest to reach via a VoIP provider, especially the Betamax clones. Keep in mind the conditions of the sim provider, like connection fee, expiry of the data, other fees.

To avoid the data roaming to initiate the callback, I would get a free DID from some country. You call the DID, the server hangs up the connection and calls you back.

Keep in mind, all local and internation sims are considered mobile numbers from the point of view of the VoIP provider.

Some international sims offere non-mobile DID, but then the incoming calls are never free.

joeko2202 · 22-01-2009, 17:35

Excellent, that's exactly the info I'm looking for. Time to do a little more research

As for the data roaming issue, I need to have a little more of a think about that. The data connection to initiate the callback would also send back to my callback server things like "what SIM I'm currently using" and "current GPS location", but I'd need to think if I could exploit that info to find a better route for the call. However, if it's useless information, then a local DID may be best.

bbob · 22-01-2009, 17:46

I have a system like that setup as part of my total phone system.

www.pbxes.com offers a vitrual voip pbx.
Using the premium service you can have 3 callback number.

You also need a voip provider for outgoing calls and making calls. I use voicetrading for example.
You need a did number as incoming line or callback number. For some countries you have to pay for others you can get them for free.

I alsways have 2 phones (my cheap china dual sim phone broke down after 2months and still waiting for replacement) I use my dutch cellphone to trigger the callback. I can a number and get a busy tone. pbxes than calls me back on my other roaming free mobile and I get a dialtone. From there I can call any number using voip at there low rates.

I also use the system to recieve calls on my did number. If someone calls the call is also forwarded to my cellphone and I can answer the call. My cost is only calling the roaming free cellphone which is around 8 eurocents for a +44 mobile.

stefandim · 22-01-2009, 18:41

Just as an addition. Sometimes when your server calls your mobile and gives you a dialtone, DTMF codes may not work properly, depending on the codec and the quality of the VoIP connection, especially when using some cheap provider.

If you trigger the callback using a data connection, you can specify the number to be dialed, so, no problem there.

If you use a DID for the callback, you can also get several DIDs and assign one of them for a callback with a dialtone, and the other for automatic callback to your most frequently called number.

Stu · 08-03-2009, 14:38

I use PBX and like it. I also popped $15 (per year) to voxalot for their web based callback system and assigned to pbxes.com. I have a global Blackberry plan and have saved their mobile web page to that phone. I have two pages of common calls and can just punch in an extension and a number and make cheap calls.

My roaming SIM collection is down to United Mobile thanks to the collapse of 09/Yackie. I used to have a Geodessa, but it fell through the cracks a year ago. Right now, I'm paying the 19 euro cents for the connection, but might start exploring my options real soon.

	(#1)
joeko2202 (Offline) Junior Member Newbie Posts: 4 Join Date: 22 Jan 2009 Country:	Personal callback server redux - 22-01-2009, 15:40 Ok, so people have told me I have too much time on my hands... I'm working on a project to try to get inexpensive cell phone calling in Europe, and working on my own callback server (using FreeSWITCH, a REST web service, and some software on the phone). Where I'm hitting a snag is the VoIP provider -> mobile phone. There's two routes I can go, either get a local SIM for each region I'll be in (which raises a question, how "tight" are roaming areas in Europe? For example, if I had an Italian SIM, and rode across the border to Austria, would I find that my costs would increase due to roaming?). The other option is the international SIMs offered and getting a VoIP termination in Europe somewhere. The question there comes from looking at the comparison chart. I'm assuming the prefixes are all mobile prefixes (e.g. +4236 versus +423), since this impacts my magical low cost routing calculator I've got chugging along. So, I'm looking for some practical experience in this. I believe the local SIM would be the cheapest route, but also the most inconvienent. The international SIM is easier, but the costs may be a problem. Any thoughts?

	(#2)
stefandim (Offline) Junior Member Newbie Posts: 9 Join Date: 08 Jan 2009 Country:	22-01-2009, 17:04 You definitely have a lot of possibilities. First, if you get a local sim in Europe, the incoming calls will be free in the home country, but the standard incoming roaming tarif in EU countries is 0.26 EUR/min. Some providers may provide cheaper incoming rates or even for free, for example, the 3 at home offers. On the other hand, the international sims offer free incoming in a lot of countries. For your type of scenario, I would select an international sim with an UK number, since they are the cheapest to reach via a VoIP provider, especially the Betamax clones. Keep in mind the conditions of the sim provider, like connection fee, expiry of the data, other fees. To avoid the data roaming to initiate the callback, I would get a free DID from some country. You call the DID, the server hangs up the connection and calls you back. Keep in mind, all local and internation sims are considered mobile numbers from the point of view of the VoIP provider. Some international sims offere non-mobile DID, but then the incoming calls are never free.

	(#3)
joeko2202 (Offline) Junior Member Newbie Posts: 4 Join Date: 22 Jan 2009 Country:	22-01-2009, 17:35 Excellent, that's exactly the info I'm looking for. Time to do a little more research As for the data roaming issue, I need to have a little more of a think about that. The data connection to initiate the callback would also send back to my callback server things like "what SIM I'm currently using" and "current GPS location", but I'd need to think if I could exploit that info to find a better route for the call. However, if it's useless information, then a local DID may be best.

	(#4)
bbob (Offline) Senior Member Prepaid Expert Posts: 499 Join Date: 20 Feb 2007 Country:	22-01-2009, 17:46 I have a system like that setup as part of my total phone system. www.pbxes.com offers a vitrual voip pbx. Using the premium service you can have 3 callback number. You also need a voip provider for outgoing calls and making calls. I use voicetrading for example. You need a did number as incoming line or callback number. For some countries you have to pay for others you can get them for free. I alsways have 2 phones (my cheap china dual sim phone broke down after 2months and still waiting for replacement) I use my dutch cellphone to trigger the callback. I can a number and get a busy tone. pbxes than calls me back on my other roaming free mobile and I get a dialtone. From there I can call any number using voip at there low rates. I also use the system to recieve calls on my did number. If someone calls the call is also forwarded to my cellphone and I can answer the call. My cost is only calling the roaming free cellphone which is around 8 eurocents for a +44 mobile.

	(#5)
stefandim (Offline) Junior Member Newbie Posts: 9 Join Date: 08 Jan 2009 Country:	22-01-2009, 18:41 Just as an addition. Sometimes when your server calls your mobile and gives you a dialtone, DTMF codes may not work properly, depending on the codec and the quality of the VoIP connection, especially when using some cheap provider. If you trigger the callback using a data connection, you can specify the number to be dialed, so, no problem there. If you use a DID for the callback, you can also get several DIDs and assign one of them for a callback with a dialtone, and the other for automatic callback to your most frequently called number.

	(#6)
Stu (Offline) Senior Member Prepaid Guru Posts: 1,091 Join Date: 11 Feb 2004 Location: Detroit (formerly Dubai) Country:	08-03-2009, 14:38 I use PBX and like it. I also popped $15 (per year) to voxalot for their web based callback system and assigned to pbxes.com. I have a global Blackberry plan and have saved their mobile web page to that phone. I have two pages of common calls and can just punch in an extension and a number and make cheap calls. My roaming SIM collection is down to United Mobile thanks to the collapse of 09/Yackie. I used to have a Geodessa, but it fell through the cracks a year ago. Right now, I'm paying the 19 euro cents for the connection, but might start exploring my options real soon.