Free Mobile Clients: SIP on the go

Here at Callcentric we can become overwhelmed with the many IP phones, ATAs, IP PBXs and other SIP solutions that run around in the wild. A phone on your desk for work, one at home for more work and then an IP PBX to connect them all together, of course for more work. Yes it’s a benefit and we love the flexibility and freedom, we really do. If you love flexibility as well then these last few words must have been absolutely comforting to you.

But what about the users who wants to keep everything centralized. These users got rid of their landlines and dock their iPhone into their various docking stations. These users don’t need the multiple points of communication. They have a mobile phone and this is the central aspect of their daily lives.

So how would one go about making such a choice? Simple, you can install a mobile SIP app that can integrate into your device and provide seamless communications. By doing so they can take advantage of cheaper international rates and use wifi instead of their data plan for features such as video calling.

In this article we provide mini reviews for some of the most popular free SIP applications:

cSIPSimple ZoIPer Linphone


Regis Montoya








*as of 9/2012








Extra features

Open source based on pjsip and benefits from new and experimental featuresProfiles for easy setup with Callcentric Barcode scanner to easily generate configuration *Push notifications allowing you to receive calls without being registered to Callcentric
*Only on iPhone

These mini reviews/evaluations are meant to provide a snapshot view of the current release of each softphone. We follow our standard review pattern and provide an overall rating for each softphone.:

Introduction: General description
Appearance: Layout and visual features and delivery method
Features: Extra non visual features
Setup: Configuration process
Performance: Call quality, stability and usability
Conclusion: General opinion on all points

We will provide each device with it’s own mini review with only the main points included. So let’s begin.


ZoIPer offers softphone solutions for the desktop and mobile devices. ZoIPer currently supports a wide range of operating systems and platforms including iOS, Android, Mac OSX and Windows.The mobile softphone offers voice calling over wifi or 3G. Recent features such as QR code scanning proves that ZoIPer has a focus on innovating and delivering a unique user experience over the SIP protocol


The mobile ZoIPer client looks pretty much like any mobile SIP client: a number pad with easy access to your call logs, contacts and configuration. Interestingly on the Android version the configuration is not accessed through the context menu button but using a Config navigation item at the top of the softphone. Beyond this the softphone is basic and won’t be difficult to use.


ZoIPer for Andoid includes your standard expected features such as voice calling, contact book integration and call logs. One unique feature which we found very useful is the QR scanner. This allows a provider to configure the most necessary SIP details which an end user could get by scanning. The user may then be required to enter only their username and/or password. The lack of three way calling and video calling makes the softphone less “interesting” But does it take away from performance?


Since we do not currently provide QR scanning information for the ZoIPer client, one would need to configure settings manually. Luckily this is painless through easily navigable menus. For specific settings we recommend the following:


Codecs aLaw, uLaw


DTMF style RFC2833

Network Settings

Use RPORT for signaling Checked
Use RPORT for media Checked


Call quality and general application performance are top notch in this client. There’s not much beyond audio calling one could do, which performs very well. We have not experienced any crashes or dropped calls in our use of this application.


ZoIPer is certainly attempting to make their name known. They’re providing desktop and mobile softphones which are stable and functional. In order to stay on the forefront of the SIP game, so to speak, ZoIPer uses common technology to create useful features such as the QR scanning. If you want a stable softphone which does what it’s supposed to do then ZoIPer mobile may fit your needs.

Visual Rating
Standard softphone interface. Nothing too obscure, but nothing to impress
Lack of three way calling or video calling take away from an otherwise excellent effort.
Simple setup, and even simpler setup when using QR configurations.
Stable performance for what it does best, which is make calls.
If you’re looking for extra features then look elsewhere. If you’re looking for stability and performance give ZoIPer a try.


Currently cSipSimple is offered only on the Android platform.This softphone offers the ability to place and receive calls while under a Wifi connection, or under your mobile carrier’s data networ. cSIPSimple integrates well under the Android operating system and is a good choice for those wanting a free usable solution. Additionally the developer, Regis Montoya, is very quick to fix any problems.


The overall look of the softphone is basic like most other mobile SIP applications. It does integrate well with ICS and Jelly Bean device by taking advantage of the built in themes. cSIPSimple has the ability to integrate with the Android dialer. This will allow yon to simply use your Android dialer to place an outgoing call, and your phone should prompt you whether you would like to send the call to your carrier’s network, or through cSIPSimple.


Like with most SIP softphone applications that are built for a mobile platform, the feature offerings are basic. Based on the cSIPSimple homepage,  the developer is actively maintaining the project and will be adding features in the future; such as video support.


Configuration is straightforward, since this softphone has a built in profile for Callcentric. The only settings that you need to supply are your username (your 1777XXXXXXX number) and your SIP password. Once you’ve supplied those, you’re pretty much ready to start making and receiving calls.


In our testing and normal use we’ve experienced little to no issues. The application itself is very responsive and does performs it’s core functionality exceptionally. We didn’t experience any software crashes or force closes when using this application across multiple Android devices, such as the Samsung Galaxy S3, HTC One X, Droid Incredible or the Google Galaxy Nexus. Nor did we experience any issues with call quality while under a WiFi connection.


With a name like cSIPSimple, you’re expecting the overall experience to be easy and hassle free. Does it live up to it’s name? Yes, we believe it does. It’s definitely a softphone to check out if you want simplicity in your mobile VoIP experience.

Visual Rating
The overall dialer interface is basic; however this softphone does have the ability to use the integrated Android dialer when placing outgoing calls.
Like with most mobile softphone applications, it has a very basic feature set.
Very easy to configure with the included wizard for the application.
Offers stability/ reliability, as well as clear call quality.
Overall a very simple phone


Linphone is an open source VoIP SIP client that is available for Windows, Linux, Mac OSX, Android, Blackbery, and iPhone.With this softphone you can make and receive calls both on wifi and on your mobile carriers 3G/4G network. Linphone also has support for Video calls.


Linphone seems to be designed for usability and while the appearance is certainly functional and inoffensive, it’s not something we would call beautiful. There is something to be said for designing for both functionality and beauty. In addition since this softhone does not integrate with the Android dialer you have no choice but to use the Linphone app to make all of your calls. The design gets across the information that you need, the buttons are well spaced and the right size.


Linphone comes with support for video calls which gives it a leg up over most other mobile softphones. The project is actively supported and, while it is a free app, it would be nice to see a paid option for the G729 codec for those that are concerned about quality over mobile networks.


Setup is relatively simple; BYOD veterans will have an easy time getting up and running. Those new to configuring devices will find setup straightforward with minimal changes necessary before you can start making calls. Linphone does not come with profiles for popular carriers, however since setup is easy most people will not miss this feature.


Linphone is quick and responsive. During testing we did not experience any hang-ups, crashes, or slow-downs. Call quality was clear, however on one of our test units we did experience low volume but we were unable to reproduce on other devices.


Linphone is a lightweight, open-source SIP client that gets the job done with few frills. With video calling support it is hard not to recommend this client. Add to the mix that it is free and works well across multiple devices it’s easy to see why it’s become so popular and one of the softphones that we regularly recommend.

Visual Rating
Basic dialer interface; isn’t holo themed on Android.
Basic feature set, however video calling gives it a full 3 stars instead of 2 and 1/2
Configuration is relatively easy but profiles would simplify it even further.
Offers stability/ reliability, as well as clear call quality.
Overall a basic, but great phone.

3 thoughts on “Free Mobile Clients: SIP on the go

  1. Pingback: Paid SIP Clients: More SIP For Your Dollar | Callcentric Blog

  2. evv rajesh


    i am working on compiling linphone into xcode .
    it was perfect till now but, when i am trying to make a call by entering some number…. displaying alert message “call failed, number did not register to service”.

    so, please any one here let me know what i have to do more….. to make it work perfectly for making audio & videi call.

    Thanks in Advance:)