Free VoIP Calling using Google Voice, Antisip, and IPKALL (and a CLI utility)

I’ve been experimenting with my FreeRunner recently and came across some articles about free VoIP.  As it turns out, thanks to Google Voice and a few extra services, it’s possible to both receive incoming and make outgoing calls completely for free.  After setting these services up, I wrote a CLI utility that combines a Python Google Voice framework with Linphone in order to make the task of placing a call easy.

Getting free VoIP

You need three things: a Google Voice account, an Antisip account, and an IPKALL phone number.  Go to each of these websites to create them.  For Antisip, you can use your Google Voice number for the PSTN Phone.  For IPKALL, you’ll need to provide the following information:

SIP Phone Number: [antisip username]
SIP Proxy:

After some time, you’ll receive a Washington state phone number.

Now, open up Linphone using either the GUI or the CLI client (probably easier with the GUI).  In the preferences of the GUI, there is a tab called “Manage SIP Accounts;” go there.  Add a proxy account with the following information:

Your SIP identity: sip:[antisip username]
SIP Proxy address:
Register at startup: yes

Now, Linphone should register.  You can try calling a SIP echoline at sip:* to see if things are working.

Putting it all together

Lastly, we want to be able to make free calls to regular phones, too.  This is where the IPKALL number and Google Voice come in.  Antisip only allows incoming calls.  When you call a number from Google Voice, it first calls you and then calls the other person, thereby acting as a link between the two connections.

So, add the phone number you got from IPKALL to Google Voice and try calling a phone number from the Google Voice interface.  It should call your SIP client first and then call the other number.


To make this process quick and painless, I wrote a quick Python script called gvcall.  Basically, it makes the process of calling a number from your computer as painless as gvcall 5555555555.  You can also use your non-VoIP numbers as well.

41 Responses to “Free VoIP Calling using Google Voice, Antisip, and IPKALL (and a CLI utility)”

  • Sorry, i tryed this whole procedore and wont working, starting by the test.

    Now, Linphone should register. You can try calling a SIP echoline at sip:* to see if things are working

  • I tried using that IPKALL service, and when I did I was told by Google Voice that the number I tried was already being used on two other google voice accounts.

    Not worth it, imho.

  • That’s odd. Maybe try requesting a new number from IPKALL? It’s possible that the number was used, then recycled (because the user didn’t use the number within 30 days), but left on the old Google Voice account.

    I do agree with you on your second point… I still think it’s necessary to have a regular phone number. This is just handy if you want to make calls from your computer quickly (and freely).

  • @mendel: Does linphone give you any errors when you try to register?

  • no, they didn’t, i have tryed the sip: and it start to call, better, trying to call but it saids “no answer” and when i tryed to call the number which i get from ipkam the sent me to VM,
    any help would be Appreciate.

    thanks in advance.

  • i just opened it again a error came up.
    Could not start UDP transport on port 5060, maybe this port is already used.

  • (I had a really long comment here but then lost it after a server crash… I’ll help you out via email).

  • Same as Zauber Paracelsus; guess some ppl just don’t update their gvoice or something….

  • I am not quite get it, WHY the antisip account is needed?
    Can’t I just use an ekiga account linked with ipkall, then forward google voice to that D.C. number got from ipkall?

  • Ha, I C. antisip is just like ekiga, iptel, or anything else who provides free sip accounts. I misremembered it for an ipkall like service in France:>

  • If you cant get the ipkall number to register in google voice, login ipkall site with your number, cancel account and make a new one. keep repeating this until eventually you will get a different error upon entering the number into google voice allowing you to reclaim the number. have google voice call the phone and your linphone should ring enter the 2 digit number google voice gives you using the linphone keypad and your set…

  • I followed the steps, and it works perfectly fine for me. I did get a message that the google number was used by another account; but they gave me the option ‘reclaim the number’, and so I did. Since, it was my google number i had no problems claiming it back. Now, I am enjoying a true free VoIP experience. The best part, the Washington # never shows up on the caller id of the other person, my google number does.

  • I can get this to work on the computer (using GV, IPKall and Linphone free SIP service [] but can’t figure out what I’m doing wrong on an iPhone 2g. Any help / suggestions??

  • I would like to learn alot more about this process. Please e-mail me at I’m trying to get SIP working on my Touch Pro 2 WM 6.5 with only pay as you go internet from Boost Mobile. I think this is the way I want to go but everytime I try to use antisip and IPKall it won’t work for me.

  • Great guide, worked perfect for me. Was recently banned from for going over free minute allowance and was looking for an alternate free sip service. So far call quality is great and no problems. The only thing that didn’t work for me was the echo sip number gave for testing. So instead, I called my local wal-mart for call testing(they are victim to all my call testing…lol) And for people having problems with ipkall numbers being registered to another google voice account….. try to reclaim the number or make a few more ipkalla ccounts…. the same thing happened to me when I first made my ipkall account…. the problem is that thousand and thousands of people are using google voice and ipkall for free voip and they let their ipkall number expire by not using it for 30 days, and never delete the number off their GV account then you get the number…. once you get a good ipkall number, don’t let it expire, there’s endless ways you can use an ipkall number for free voip calls just by changing sip providers…..I use this with my htc hd2 and android with a sip client off the market…. works great as a home phone….

  • I’m glad to see that people are having success. One other service you might try is sipgate. Their free service provides a phone number and a SIP account, so everything has been taken care of for you. When I signed up for their free service, they provided only a certain number of minutes for outbound calling, but again, you can use the Google Voice trick to bypass that. They may have changed their model recently though.

  • The basic process is valid. Just stick with it. In place of AntiSIP, try callcentric. That does pretty much the same thing.

  • Thanks jwc for these instructions. The SIP echoline had positive feedback or something, an awful sound that just kept getting louder, is that what’s supposed to happen? I didn’t stay on the line very long. Actual calling works but the call quality is very poor, it sounds like it’s being routed through Jupiter or something. (And I’m not that far from WA, I’m in TX) Also, the echo is kind of annoying, I say something then hear it on my own earpiece and then hear it on the receiving earpiece. (Calling my landline for testing purposes.) Is there anything I can do about this, or is this a consequence of “it first calls you and then calls the other person, thereby acting as a link between the two connections” ?

  • That’s definitely not right. I’ve never experienced any sort of problem like that before. What does your audio setup look like? I’m wondering if you’re getting feedback from your mic picking up what it hears from the speakers.

  • Hi, my audio setup is a Sennheiser headset/mic. I don’t think that’s the problem because sound quality is great when calling directly through GV (same computer, same headset). But I’m not worrying about this procedure anymore, the only purpose of linphone was to validate the ipkall number in GV. Now I’m trying to set up my itouch 1G to send and receive calls. (Doing it from the ipod was really the point of undertaking this procedure, because if I’m on the computer I can just use GV directly.)

    Using my antisip and ipkall info, but can’t use linphone on the touch because firmware is only 3.1.3 (jailbroken in order to use backgrounding and fast app switching). So I’m using fring instead. Again calling my landline for test purposes, when I call the landline from the ipod, as expected fring rings, I answer it, the landline rings, I answer it, but it goes straight to voicemail. Or sometimes, I can’t hear anything on either of the phones. But this might be due to bad wifi. (By the way, the problem is not the audio/mic in this case either. I can’t use the headset but I also have a dock mic/speaker that I’ve tested and it works fine.)
    When calling the ipod from the landline (must use a phone card with the landline), the ipod doesn’t ring until after I hang up the landline, then it will notify me of a voicemail. Well, I’ll go somewhere with better wifi and then try again.

  • I should mention that it’s not supposed to go straight to voicemail, call screening is turned off.

  • Does sipgate serve the function of antisip or is it more like ipkall?

  • The reason I asked the previous question is that I tried the procedure given here: but instead of sipgate I used your antisip/ipkall combination. Wondering if that is right. Can’t use sipgate because it requires a cell.

  • Hmm, I’m not sure about your call issues. It could be a bug in Google Voice’s service.

    Sipgate handles both the functionality of Ipkall and Antisip. That is, it provides you with a free SIP account (like Antisip) and connects you to the phone world (like Ipkall)

    Can you sign up to sipgate with your Google Voice phone number? I don’t remember having to use my cellphone at all to sign up.

  • I think sipgate’s cellphone signup is a recent development. Thing is, they ask what carrier. I tried the GV number with several carriers to no avail. Other people are reporting the same thing. I’ll keep looking at this, thanks.

  • Maybe someone could send me a sipgate code please?
    “pinchemao” at “yahoo” dot “”
    Here’s the page:

  • Well, tried again w/ registering ipkall numbers, and viola, got one that worked with google voice; happily using my phone now with google voice callback app, gvoice app/gvoice, csipsimple app (I have an old phone, dunno if this is the best sipphone app but it works). My ipkall number directs to my free ekiga sip account ( signup –> good alternative to skype there). Don’t have a sim card, but ~$100 for a droid that gives me unlimited free calling/text/data over wifi… can’t beat that.

  • Old as in ancient droid; I just took my phone out the packaging brand new… kinda strange for a 3 year old phone…
    Anyway, sorry for the double post

  • the set up worked as described. i can use the google voice freetalk app on my windows phone 7 to call a regular (cell) number BUT… all that happens is my linphone just rings and rings and rings! when i click decline on the linphone, the cell phone i dialed via GV rings, but no voice connection. another weird thing is when i call a different cell number, the linphone rings and rings, but when i decline, the other cell phone does not even ring. in short, this is not working! what should i do?

  • 1) the “other” cell phone i tried calling did ring i just didn’t know cuz it was on vibrate :s
    2) i also got this error message:
    Could not start UDP transport on port 5060, maybe this port is already used.

    is there some sort of conflict between antisip and linphone? they both appear to be receiving the same phone call simultaneously. i REALLY want this to work! can someone help?

  • thank’s ! nice guideline. i am also interested in the tecnical background how the pieces fit together. any big picture or recommended reading? any feedback appreciated, peter.

    fgmicrotec on bb 8520 ;-)

  • I’ve tried setting this up and I got no progress what so ever. Can someone be of some assistance please?? I’d really appreciate it.

  • Trying to get this to work with Ubuntu 12.04
    First problem 5060 is used.
    ok, switched proxy
    next. followed the steps closely
    tried another number..
    I am giant squid of frustration…
    Write a clear guide in the future

  • I am a giant squid of frustration here…
    this guide doesn’t tell you where to enter the password

  • it’s great to be me

  • Yes, this works but it’s a bit outdated and you need some tech savvy to figure it out. I found a simpler updated method at
    It’s basically the same as this, uses CallCnetric, Ipkall and GVoice.

  • Works like a charm. I’m not sure that I can receive calls yet, don’t know what that’s about, but at least I know that I can make them! Haha! I was laughing with glee at this trick working, free calls for me!

  • I’ve heard in 2nd half of 2012, Google will stop free calls and may make the service pay only. However, its going to be end 2013 soon. How long more before GV is free? Any idea anyone ?

  • Hi there. I’m Jonathan Torres. I am just wondering if you can develop VoIP apps for my website where all my members in the philippines can have access to VoIP service. Do you have a number where I can call? I tried magic jack and this is my number 9092334347. Thank you very much

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