Tonight I was playing around with my new HTC TYTN (ATT TILT) and found this blog explained there’s a hidden feature on Windows Mobile – an included VOIP client.

REALLY? yup. FREE? yup. Not kidding.

It’s pretty easy to install too, just follow these steps, and then you’re up and running in no time making crystal clear VOIP over WIFI calls.

Note, you will need a membership to XDA Developers to gain the best of this. Otherwise you can download the files required at the bottom of this post.

Instructions to get Free (WIFI) VOIP SIP Calling on your Windows Mobile Device Using Asterisk:

  1. Visit this Page on XDA Developers. Download the VOIP Soft Client.

  2. Install the Client to your Windows Mobile Device in the regular Fashion.

  3. Soft Reset your Windows Mobile (Unsure if this is required).

  4. Download and Install this Configuration Utility from XDA Developers to your Windows Mobile Device in order to configure your SIP settings.

  5. Enter the configuration for your SIP server.

     Provider name: myuser  
     User account: 123  
     Password: 321  
     registrar address: port 5060 UDP  
     proxy address: port 5060 UDP
  6. Save your SIP settings. Soft Reset Device again (This appears to be needed).

  7. You should now see “Internet Calling” on your home screen. Verify that it has connected to the account on your Asterisk Server.

  8. We set ours to “always prefer internet for calling”. This way when we are in range of a WIFI network that the phone knows about, it will always try internet calling instead of 3G/GSM first.

That’s it. Easy eh. I’m sad to admit I’m actually liking this Microsoft stuff for once :(.

Here are the files if you don’t have an XDA (Free) account.



Comment by Abiola on 2008-10-29 19:34:39 -0500

Hello guys, ur post is awesome. i hv successfully installed the 2 programmes. i can see “Internet Calling:Available” on today`s screen. the question here is whats next. i installed this to that my mobile phone can be part of VoIP network in the office.

We are using switchvox appliance AA350 and we hv wifi network in each floor of our office building.

I look forward to the next step

Comment by Matt G on 2008-10-29 20:07:11 -0500

Hi Abiola,

Thanks, glad you liked it.

The next thing you would do is go to your programs menu, find the “SIP Config Tool” and configure your PBX information in there. The app is a little finicky and you may have to turn internet calling on and off again in the phone settings menu. I’m pretty sure this is only available after a reboot of the phone so make sure you reset it.

Note that the way the MS Voip app works, the sound only comes out of the back speaker, we’re hoping for a fix on this, but figure the are under pressure from the carriers since they don’t want free VOIP on their phones.

I’ve seen people talking about Fring as a client, but I have not tried it as of yet.


Comment by Kemal on 2008-11-24 17:14:33 -0500

I’ve installed it successfully and connected to my own voip provider ( I know it’s not free But I don’t have an asterisk server. I have also set the device settings to use whenever internet is available. Yet it still makes tries to make a call from my GSM line… PLease help !!!!

Kemal — Thanks this is an awesome post

Comment by Matt G on 2008-11-24 17:53:19 -0500

Hi Kemal,

Interesting, I am able to call the phone, and call out from the phone. But, it’s still a little finicky. Have you tried rebooting the phone to see if that helps? I notice that mine says “unavailable” sometimes, even when it is available, and a reset fixes it for some reason.


Comment by B0rks GPS functionality on 2009-03-01 18:07:16 -0500

Tried this with a bunch of other stuff on my HTC Raphael and soon-after noticed that the inbuilt GPS has stopped working completely.

I asked a few questions on XDA-Developer and a few others said this VoIP bundle did the same for them.

The only way I could fix this was to do a hard reset and reinstall all my apps (except the VoIP!)

Be warned!

Comment by Matt G on 2009-03-02 09:30:26 -0500

Interesting, thanks for pointing this out. I gave up after a while with this. I don’t understand why the audio comes out of the back speaker, I was sure with one of the roms I ran it was coming out from the regular speaker, but every rom I try it with lately it’s coming out the back, which is a pretty big pain in the butt.

I hadn’t noticed the GPS – I use this infrequently, thanks for alerting us though.

Comment by amrutraj on 2009-03-13 01:42:06 -0500

Thank you for the info.
Apparantly you can scrap your sim card altogether as long as u r in a wireless internet zone coz u can get an INCOMING NUMBER from for FREE. Its extremely easy.

in the “SIP Phone number:” field just enter your username of SIP service (In my case it is “trojan07” and SIP proxy is “” They will send you a phone number for incoming calls.

THATS IT. Now u can receive incoming calls.

When it comes to cell phones windows mobile seriously rules (as opposed to iphone) as long as you know what u r doing. Thats a lot coming from an apple fanboy.

Comment by NKH on 2009-03-27 16:20:16 -0500

thank you for the information but I use it one time & still it deducting mony from my account & I don’t under stand what is the meaning of Using Asterisk:

Comment by NKH on 2009-03-27 16:21:43 -0500

sorry another question it is just for recieving calls

Comment by Michael on 2009-05-18 07:40:30 -0500

hi! i’ve sucessfully installed the two files. the status of my Internet Calling is available but I can’t make calls…

Below is my SIP config:

SIP proxy: 91.151……….. <- asterisk server
Username: asterisk username
Password: asterisk password

Also, where will i put the Extension Number for the mobile that I made in asterisk?


Comment by htc touch pro not working on 2009-08-15 04:21:13 -0500

everything installed fine and the config tool let’s me do it’s thing but the htc touch pro (win mob 6.1) and i can’t see the “internet calling” option anywhere. this is my first win mob device so maybe the home screen is different. i went into phone app settings thoroughly and see nothing about internet calling.

Comment by Fahad on 2009-10-20 14:16:49 -0500

I have Schap’s WM6 Pro 4.00 ROMs on my HTC Tytn II. It’s working perfectly fine. As far as VOIP is concerned; I can receive calls to my phone but when ever i dial call from my mobile through VOIP it shows an error like “Cannot complete the call……. verify the number or try again later.”
Now I have tested something.. Called from my PC softphone to my SIP account configured in HTC and succesfully received the call.. from my phone i selected to transfer the call and dialed a SIP number and it worked!!
Thats something confusing for me now!! I think it’s something to do with “Dial Plan”.
Something to share with you guys is that the sound of phone call is normal (not on speaker phones)

Comment by Lee on 2009-10-28 12:54:43 -0500

I’m using an HP iPaq 510 which has WM 6.0, WiFi and a built in VoIp application. I’m wondering if it is that same as the one in this article. The problem with the App on my phone is that there is no STUN settings. Hp states that it is not meant for use outside of your office. I’ve found that, even though, when roaming, it will register (most of the time) with my VoIP PBX at home, the voice path will be only one way, if at all. The PBX will only see the private IP of he phone when behind a router. Can someone, that has added this application to a different unit , let up know if it has STUN?
Thanks, Lee

Comment by Grayson Peddie on 2009-11-13 16:07:44 -0500

Installation to my Sprint Samsung Ace will not work.

Q: When installing, I get an error that says, “Installation was unsuccessful. The program or setting cannot be installed because it does not have sufficient system permissions.” What do I do?

A: Some mobile operators may not allow installation of certain applications. Contact your phone service provider for more information.

Unfortunately, I don’t want to let Sprint know that I want to install VoIP client with configuration tool.

I’m trying to install this in Windows Mobile 6.1 Standard. Any other options? I am using 3CX Phone System (like Asterisk but for Windows Web Server 2008).

Comment by Esteban Barrientos on 2010-03-12 11:05:25 -0500

Hello and thanks for this post, i have an LG GM730f and i installed both programs with no errors, i configured my account with sip tool but i don’t see the internet calling anywhere so i can call using my sip account. Any pointers?
Thanks in advance,

Comment by Bhargava on 2012-09-18 01:23:36 -0500

i installed both files,(didnt configure astrek..just typed
my home screen says
plz help