Tuesday, February 14, 2012

How to make cheap local calls with your Android or iPhone

Everybody knows Skype or Google talk, VoIP applications that allows users to make free calls computer to computer and cheap long distance calls from computer to traditional phone networks.
Long distance but also short distance! The Lao government last smartest idea (regulate the local market by fixing a minimum rate of 800 LAK/mn) has drowned mobile operator revenues and pushed customers to find alternative ways to communicate and save money.
In this article, we will explain how you can make local calls more than 3 times cheaper using your smartphone and a regular 3G data plan from any operators (Unlimited plans are of course preferred even though you will see that a VoIP call is not that expensive for your data balance).

To set your system up, you don't need to recompile your smartphone kernel, hack the mobile network or steal the balance of someone else, just a smartphone, a credit card (yes that is the tricky part of this tutorial but you can also use bank wire transfer) and lets say 30 minutes, coffee break included.

  • Step 1: Open a VoIP SIP account
In our tutorial, we will use callwithus which offers the very competitive rate of $0.03363 USD/min (269 LAK/min !!) for any Lao destination (mobile and fixed). You can also use Mydivert.com (240 LAK/min) or any VoIP provider you may find cheaper.

Create an account takes around 30 seconds, just enter your details and validate. You will receive a confirmation email and the details to configure your VoIP phone.

Then, just login and buy credits (via Google Checkout, Paypal, credit card, or bank wire transfer if you are patient...)

At it is your first order, you will have to wait a couple of hours for your account to be verified and credited. It gives you some time to install your sip phone.

  • Step 2: Install and configure your VoIP SIP Phone
There are many SIP phones for Windows, Android, iPhone. The only thing you need to verify before downloading the SIP phone is the G729 codec support.

G.729 is an audio data compression algorithm for voice that compresses digital voice to a bitrate of 8 kbps. The quality is good and the data consumption pretty low, perfect for any data plan !

Here is a list of SIP Phones that supports G729:

We will focus on CSipSimple but the configuration is pretty similar on any other SIP phones. The design and the stability of this VoIP SIP phone is truly impressive.

  • Download it from the market and launch it
On the first configuration menu, you can choose to integrate the SIP phone to Android dialer. That means that everytime you want to call someone, Android will ask you if you want to place a normal call or a VoIP call. If you don't choose this option, you can still call your friends through VoIP by accessing CSipSimple via the application menu. Coming back to the configuration, you will have to select whether you want to use VoIP only for outbound calls or also to receive calls. This feature can allow your friends to call you from sip to sip for free.
Please tick the last option that is a kind of disclaimer saying that your mobile operator allows you to do VoIP calls on its network.

Then, tap on add account and scroll down until you find the green Android robot (basic).
  • Enter an account name (whatever your want)
  • Enter the username, this is the one you received by email
  • Enter the server name, for callwithus: sip.callwithus.com (all the configuration details can be found here)
  • Enter the password, it is your callwithus account password.
  • Validate, the sip phone will try to register. If everything goes well, it will display "registered"
  • If your account has been credited, you can now use the dialer or your contact list to place a VoIP call, just click on the call button and choose "Use: [the account name that you configured]"
  • That's it, you can now call in Laos or any other destinations in the world at very low cost simply using your 3G or even better your WiFi home connection

"But finally how much does it cost me?"
You are charged by the VoIP SIP provider (269 LAK/min for callwithus) and then charged for data consumption (with a 3G limited plan). On an Ethernet link, the G729 codec consumes totally 31.2kbps (codec bitrate 8kbps + payload + overhead). 3G is not an Ethernet link but we will state as if. On this article, we have seen that the average price per mbyte in 3G is around 40 LAK. The data usage per minute of a G729 call is then 10 LAK.
Total rate: 279 LAK/min instead of 800 LAK/min. More than 3 times cheaper!

"And how is the call quality?"
G729 call quality is very good with a decent data connection. But such as long distance call, there is a noticeable delay that can be a bit disturbing during the conversations. But for this price, who will complain?

The network quality is really important to enjoy a good VoIP call. Thus, from our test bed, we strongly recommend the limited data plans from ETL and the unlimited data plan from Beeline. The others plans have failed our test bed regarding voice quality (abnormal packet loss for LTC and very poor quality for Unitel unlimited plan). This is of course a completely subjective advice as it will clearly depend on your coverage (location).


  1. Actually if you have your friends install this app as well, the call rate per minute between you and them falls down to 10 LAK, and you don't need to use a credit card.

  2. Sure ;-) But your friends should have a smartphone.

  3. Calls made to land line phones are economical when compared the charges imposed on calls made to mobile phones. Especially when you are using internet voice chat applications, you can enjoy amazingly lowest rates when you call a land line phones. Now that with this app, the possibility is virtually unlimited. Cool post, keep it up.

  4. Could you send and receive SMS with the sip number?

  5. When you enroll do u get a new provided phone number ?

  6. Humm no, it is for callout, you dont need a phone number.