VoIP POTS Emulation on FXO with MagicJack

July 25, 2007 by Garrett Smith

MagicJack was founded by telecom veteran Dan Borislow of Tel-Save (TalkAmerica) fame. MagicJack provides VoIP service based upon a proprietary USB device which retails for $40 and includes a free year of domestic calling service. After the initial year of service, 1-year renewals are $20.

MagicJack has been shipping their device for a few months, and recently announced a promotion for SunRocket refugees, but it is unclear the number of subscribers MagicJack has.

MagicJack requires a PC, and their simple device plugs directly into a USB port. From there, you connect a traditional analog phone into the RJ11 jack on the USB device. MagicJack assigns you a DID number, and you are ready to make and receive calls. MagicJack also offers free calling features including voicemail and call waiting.

I purchased one of their devices about a week ago, and I have not gotten around to testing it, but it got me thinking. I intend to pair the MagicJack device with an Asterisk based open source PBX, running an RJ11 patch cable between their USB device and an integrated FXO (Analog POTS Line In) port on the PBX. It seems logical that you could use the MagicJack device to emulate traditional POTS service, and create a Zaptel trunk on the Asterisk PBX (Which is, in reality, a VoIP trunk).

If this works, it seems to me that it would be an inexpensive and easy way to incorporate VoIP trunks into an IP PBX for a small to midsized business customer, and could be “self-provisioned”

I’ll report back on this in a week or two with the results of my testing.


  • Ash

    Any luck with this ? I would also like to give it a try if you have had any luck.

  • Luke

    Sounds pretty logical. It should work, please don’t forget to tell

  • Asterisk

    So how did things work out? If I understand correctly, the RJ11 portion would be connected to the FXO card on the Asterisk box, and the USB side would be connected to a Windows PC. With this setup, how many concurrent calls would the MagicJack be able to support? In a regular Linksys ATA, there are usually two RJ11 ports for 2 separate lines. So in short, how would you be able to handle the multiple calls coming in from your Asterisk box.

  • Randall

    It works, but I would like to eliminate the magicjack device and have asterisk register with magicjack directly, since magicjack uses sip. I have asterisk installed on a wrtsl54gs and a mp104 sip gw and I want to keep everything low power devices. I have an old laptop, but the voice quality kind of sucks. A fanless little pc would work great, but they’re kind of expensive, but I think ideally the best solution would to have asterisk register directly. I just started looking into this, but shouldn’t we just need the sip username and password?

  • Jeremy

    Interesting device. I was just considering purchasing this so I could attempt to use it with my asterisk setup. Randall, have you tried using the magicjack while running a packet sniffer like wireshark? This may give you very helpful info for integration. It also seems they have a softphone available? That may be the ticket right there,assuming they didnt try to lock down or change normal sip stuffs…

  • Jeremy

    Then like a sign from God I see there running a 30 day free trial offer. I’ll crack er’

  • Guilou0875

    As most of you I have the magicjack and I was able to get it to work on the astrisk, tixbox and Elastix. works fine as a Zap trunk I can even use it with hylafax. I thought of getting my sip credentials and use it as a SIP Trunk. so I can get red of the windows machine and the MJ USB adapter. I could get the username and password but the password is MD5 encrypted. which is a pain to decrypt but possible. MJ will be able to sell a lot of these babies if they release or leak how to get the sip credentials. their software is a pain they want you to see the adds but I’m locking it any way with the 3ed party software the nails is it in the try for good. sorry magicjack the idea is good but I should be able to do anything with what I own. any how if I’m lucky I will get this unlocked. stay tuned and if any of you is able to get it to work before then please feel free to email me [email protected]🙂

  • Jeremy
  • Victor

    I used our MJ as ZAP trunk on asterisk.

    But after dialing a number, I only get a dial tone from MJ. Seems like asterisk wasn’t able to actually dial the number. I am sure that my outbound route is correct because I just added the zap channel group to my existing route trunk sequence.

    Any suggestions on how to fix this? Thanks.

  • Guilou0875

    Hello all, it has been a while!

    username = Eyourphone01
    password= use pmdump to get your password (20 charters )


    2- Victor check the CLI while dialing to see the issue you’re having with your ZAP.

    asterisk -rvvvvvvvvvv

    make sure that the outbound settings are set correctly.

    you can restart asterisk just to make sure

    I advise you to use * version if you are using an old TDM card. Some of them are no longer supported with in the newest version of *.

  • Dr.T.

    I am using MJ as a ZAP trunk with SPA 3102, and it gives me the same problem as Victor. Dial tone and can’t dial the number through SPA 3102. The settings are correct. I am thinking of cracking MJ and get the SIP on AC-211. Any ideas??

  • DJP

    I also got the dial tone like Dr. T and Victor. I think MJ has disabled the use of FXO as pl will use high volume of calls. This happened after their major update in January. Any solution?

  • Im using the MJ with Cisco CUE/CME. Use CONNECT PLAR where the extention is my autoattendant. Then you can xfer out to other extentions and/or VM. Works ok – only problem might be IOS related, When I send the PLAR to a phone it worked flawless, when I started sending it to AA the FXO is hung for 2 min. after I hang up. If I roll to VM it hangs for longer as the call acts like its on hold.

    Not done playing around yet – I think it makes for some fun lab time.


  • Hi,
    Please cancel my connection I lost my magic jack and don’t like some body else to use it. I bought it from Hamilton through your web site http://www.themagicjack.ca in Sept ,9,2009 Please Replay,
    Thanks ,

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