Is Linux Voice over IP Ready?

A Voice over IP primer with special attention to using it on Linux.

Download from the Skype site (see the on-line Resources); packages are available for SUSE, Fedora, Mandriva and Debian.

Installation: I opened the downloaded file directly in the system installer. It shows up in the Internet menu in GNOME after the installation is finished.

Figure 6. Skype—Connection Established

Getting started—registration: register from inside the client. Choose a user name and password. Enter your e-mail address if you want to be reminded of your password later on. In the contact list, select or search for the person whom you want to call. You can ask permission to be notified when that person is on-line.

Figure 7. Skype—Contact List

Impressions: Skype is easy to search by name, city and country. When you start it up, you will see a list of missed calls and contacts that are currently on-line, which is quite handy.

Skype can be configured to use PC speakers for incoming call alerts and a headset for actual communication.

Figure 8. Skype—Call List

In the call list, contacts can be displayed by name, or you can sort by incoming, outgoing and failed calls.

On the downside, the application does not seem to be very clean. After a while, I could not log in anymore, and it turned out that five instances of Skype had been running simultaneously on my computer, even though I used the buttons and menus to quit Skype. Also, it does not seem to be very stable on Linux. I had what appeared to be remote sound problems, but the problem was local and could be solved by stopping and starting Skype.


Download from the CounterPath Web site (see Resources).

Installation: extract the archive to a folder in your home directory; the default name is xten-lite. In this folder, you will find the executable file, xtensoftphone.

Getting started—registration: right-click on the soft-phone image that appears at startup. This starts the Audio Tuning Wizard, which allows you to select audio devices. Select /dev/dsp1 when using a headset. Adjust the speaker volume and voice recording volume according to your needs.

You can register at to join the CounterPath community, or your system administrator might have set up a private service. I used the X-Lite interface for testing with the Asterisk service at work. In both cases, you need to provide a login name and password, which you get either from the CounterPath registration on the Web site or from your administrator.

Figure 9. X-Lite Controls

Impressions: X-Lite is the only application on this list that actually tries to look like a cell phone. You can select a codec according to your needs. For instance, choose the GSM codec for low-bandwidth usage or when you are in a conference call. Select the g711a or g711u codec when you are in a one-on-one call, and bandwidth is not really an issue.

Figure 10. X-Lite during a Call


In Table 1, several aspects of the four applications are compared. For readability, features are restricted to those affecting telephone capabilities. All applications have many more features. I list only those that are different among applications.

Table 1. Comparison

Maintainer(s)Damien SandrasWirlab Research CenterSkype Technologies S.A.CounterPath Solutions, Inc.
LicenceGPLGPLproprietary freewareproprietary freeware
PlatformsGNOME, KDELinux (Qt)MS Windows, Linux, BSD, Mac (Qt)MS Windows, Pocket PC, Mac, Linux
ProtocolH.323, SIPSIPproprietarySIP
Behind firewall/proxyyespossiblepossiblepossible
PC-to-phone callspossiblenonon-freenon-free
Video conferencingyeslimitednoin Pro version (non-free)
Rating from 1-109878


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Hi all. I've always been a

Ben S's picture

Hi all.

I've always been a Windows user, and with the latest system crash (lsass.exe error following a registry defrag) had to reformat and reinstall everything. I've been reading a lot about Linux and am tempted to try it. I've listed the features that I usually use and got down to 2 that I can't seem to replace: MSN and voip.
For MSN, I found aMSN, but as far I've read it doesn't support voice calls. I know that there is Skype, but my girlfriend's internet is really bad and Skype calls won't work. They work in MSN though.
As I live abroad, and my parents are not computer-savvy, I use a VOIP provider that allows me to make free calls to landline phones (don't know if I can mention the name here), which saves me a lot of money. However, they don't seem to have the interface for Linux - they have a link for Mac and Linux users, ask for a signup and that's it. It's a dead end. I was wondering if you are aware of any voip provider that allows free calls and operates under Linux.
If not, I guess I'll just wait some more time.

Globe7 has Launched its

bradley's picture

Globe7 has Launched its Linux version in different versions where calling PC-PC is free and call landline/mobile at world's lowest rates.
Enjoy 1GB free space by uploading your favorite videos.Enjoy the other features like SMS,Watching Internet TV,SMS,Follow ME services.



Anonymous's picture

I have tried this,it is obsolutely good,watching TV and calling any destination is really great.

Linux Voip

cherry7's picture

I Have used Globe7 Linux softphone,where Voice Clarity is Excellent,calling PC-PC is Free and calling to any Landline/Mobile are at low rates.Can make Live Chats and send SMS,Create our own channel,communities.

Linux Voip

cherry7's picture

I Have used Globe7 Linux softphone,where Voice Clarity is Excellent,calling PC-PC is Free and calling to any Landline/Mobile are at low rates.Can make Live Chats and send SMS,Create our own channel,communities.

Disappointed . . .

bbc's picture

There are lots of confusing and misleading statements in this article. If you are going to spend time reading it, make sure you verify anything it says with your own research. The author didn't do that for you.

As for VOIP . . . I have been using Asterisk for two years. It works great. It talks to about any service. It talks to about any softphone. It has hardware interfaces for FXO and FXS. And, it is well supported . . . and tough as nails.

As for Linux as a desktop, voip/sound platform for softphones . . . pick your sound cards wisely. Don't get anything cheesy . . . and don't get anything that is really "edge of the envelope" . . . It likely won't work. BUT . . . with pretty standard sound-blaster-ish hardware, every softphone I tried worked fine on Ubuntu.

One thing the author says that I definitely don't agree with is the seperate USB sound device. That is a bunch of B.S. The author said that because it sounded good . . . and/or it works on Windows. It doesn't work well in Linux at this time.

And, forget the B.S. about encryption . . . SIP 2.0 supports it natively. All you have to do is turn it on.

Last but not least . . . is Linux ready for VOIP . . . "You bet it is!" It is so ready that I have seen dozens of products based upon Linux/Asterisk/SER and many others . . . and I would know . . . I work for a phone company.

What keeps Linux from being the VOIP desktop/softphone platform of choice isn't VOIP readi-ness or sound quality . . . It is the adoption of Linux as a desktop.

All in all, the author was lazy . . .

I think you completely

Caglar's picture

I think you completely forgot that Skype, Wengo, Gizmo and all these other programs do NOT allow to log into another server but their own ones. I have a Voip account from a provider, which has its own server, but Gizmo, Skype... will never allow me to use their software with another provider.
If you want to do this, you really have to use Ekiga oder KPhone. Ekiga is the best choice for me, since it has a really cool user interface which Kphone doesnt have. Xlite is also able to use other servers, but it isnt able to hide into the system notification tray, which makes it very unusefull if you want to be reachable all the time.
I think projects like Skype, Gizmo and Wengo should get a little more open and allow the user to chose THEIR provider.

Way off base

Brian A. Vincent's picture

Wow. I really find this article way off base and completely missing the whole concept and state of the art in VOIP.

Okay, there's some good info in here. But there needed to be a huge disclaimer up front that says, "This article is not about Voice Over IP as much as it is about various software clients you can use on your computer."

The state of VOIP is way, way beyond this article. VOIP not connected to PSTN is completely useless. Sure, it might be cute, fun, and possibly let you talk to Mom and Dad, but useless. The real state of VOIP completely integrates with the PSTN and you can call anyone, anywhere and likewise they can call you. The real point of all these SIP clients is to connect on the backend to a real PBX, like Asterisk or even something really advanced like I3's CIC platform. Register up and call anyone in the world.

Wanna talk about VOIP? Talk about Asterisk. Talk about Polycom sets. Talk about Cisco switching to SIP. Discuss real telephony features, like integration with speech recognition and voicemail. Talk about the things that people are barely thinking of.. text to speech applications using festival and advanced ACD options like multisite call centers with automatic load balancing of queues.

Ain't nuthin' interesting about a SIP client. The magic is in the backend and Linux is beginning to kick some serious ass there.


David Abreu's picture

what do you mean by PC-to-phone calls possible (!?) how's that? could you explain us a little more, please.

What about Linphone?

Anonymous's picture

An article about Linux VoIP, but not mentioning, which became quite mature since a couple of time.

This disqualifies the whole article.

the biggest feature of skype

Viktor's picture

The article left out one huge difference between the mentioned programs, and this difference is its subscriber base.

I tried before Gnomemeeting (at that time it was called like this), then I tried KPhone, later on Skype, and finally I installed Wengo and Gizmo too, but today I am only using Skype. Why? Because all my friends use it too!

We are talking about communications, a social phenomena that can be modeled using some sort of networks. (Like network economics.) And from the point of view of the badly informed end user this is the critical fact: how many people use the same program. It is not about protocols, server and client sides, no. The main feature is that I want to be connected, and Skype gives it to you.

Re: the biggest feature of skype

Anonymous's picture

the biggest and most important feature of Skype is encryption which is enabled by default.

How gullible. Everyone who

Anonymous's picture

How gullible. Everyone who cares about security would never trust a methode for encryption, if you dont know how it works. And as it is closed source, you have to trust them to use good encryption and not to deceive you. And give me reasons why to trust Skype Tech. Even worse, by using Skype you are let to feel safe, but Skype Tech. can always decrypt your data. That is one of the best reasons not to use Skype.

Better than nothing

Anonymous's picture

While I fully agree with your sentiment about secret encryption methods, having those is for me at least better than nothing (like Ekiga, sadly). With Skype, at least only the company can spy on me, and not every router on the way.

RE: Biggest Feature Of Skype

Len Morgan's picture

Your argument that Skype is best because it has the most users (right now) is the same argument countless IT managers use to continue using Windows instead of a better, more stable OS (like Linux). Pure numbers don't make a better product, just an arrogant supplier.


Anonymous's picture

The article completely fails to mention the potential security issues.
H.323 and SIP require that the system firewall be opened to incoming UDP connections from each and every potential call partner for all ports from 1024 upwards. The 'each and every' could probably be best translated as 'from anywhere'.
This could expose a lot of potentially vulnerable applications to incoming packets.

Opening ports...

Toby Haynes's picture

H.323 and SIP require that the system firewall be opened to incoming UDP connections from each and every potential call partner for all ports from 1024 upwards. The 'each and every' could probably be best translated as 'from anywhere'.

That's so far from true it's not funny. There are a few ports you *might* need to punch open for comms with Netmeeting but we are talking unprivileged ports 5000 to 5100 if you happen to run Symmetric NAT (about 1% of routers).

STUN support cuts down this need entirely. From the Ekiga FAQ:

Ekiga has extensive and improved NAT support thanks to STUN. In 99% of the cases, you do not have any configuration to do, and you can even be reachable from the outside without any port forwarding.

Go read up at before spouting more uninformed comment.

Toby Haynes

Skype and lots of connections

Anonymous's picture

I've noticed Skype making a lot of connections and wonder if it was using my machine as part of the skype architecture. Even with the firewall blocking incoming connections its hard to block outgoing ones without stopping Skype altogether, so I no longer run it. I'm on a fairly limited broadband account at the moment and don't want to run out of bandwidth allocation.

A firewall will not stop

ka9yhd's picture

A firewall will not stop Skpe from connecting to its servers.

I suggest you read this article about how Skype and other P2P applications are poking holes in firewalls to communicate.

Yes, Skype can make your computer into a server

Anonymous's picture

Yes, Skype will take your bandwidth if it wants to use your machine as a server. You don't have control over that.


Anonymous's picture

Despite only offering an *ancient* version for Linux, the one feature Skype offers, which no one else seems to have figured out is a basic requirement, is end-to-end encryption of all communications.

Why the heck isn't there some encryption functionality built into *every* VOIP app by default?!?

Re: Encryption?

Lindsey Rockwell's picture

Gizmo Projct is one with encryption. You can always install Zphone in both ends to gain "safe lines".

Gizmo is propritary

ka9yhd's picture

Gizmo is propritary software, that is.... you can only use it with their service and no one elses.

Linux isn't audio-ready.

Anonymous's picture

You still cannot count on hearing your phone ring, or not conflicting with a music player or Flash website that happens to be loaded..... because the OS allows any application that happens to be using /dev/dsp to block audio.

Software audio mixing should be standard behavior, but it isn't with Linux. So users must know about wrapper-commands and buzzwords and acronyms, and keep track of which type of audio app is running at any given time, in order to make these apps work together. And they are rudely told they didn't buy the "right" soundcard with multichannel hardware for $50 extra.

Audio output shouldn't require ANY effort from the user to 'manage' the audio-capable programs they may have running.

Here is another person's experience with Linux audio.

That's a problem with OSS,

Anonymous's picture

That's a problem with OSS, which was depreciated years ago.

These days decent applications use ALSA, which has software mixing capabilities.

If ALSA doesn't take over

Anonymous's picture

If ALSA doesn't take over the /dev/dsp functionality, then that's ALSA's fault. In the end, there's simply no excuse. It's a gross oversight to assume end-users will learn what OSS and ALSA are, and then uninstall anything that uses OSS.

> That's a problem with OSS,

Anonymous's picture

> That's a problem with OSS, which was depreciated years ago.

So if that is still a problem today then it's ALSA's fault!. ALSA completely sucks!. Have you ever tried programming with ALSA?. To write a 25 line piece of OSS code I have to write about 50 lines in ALSA and they do the same thing.

"So if that is still a

Anonymous's picture

"So if that is still a problem today then it's ALSA's fault!"

No its the fault of all the applications that still use OSS, Skype being ther perfect example of this.

A completely useless article

Anonymous's picture

A completely useless article from someone obviously unaware of VoIP technologies and applications. Get a clue or do a minimum of research on the subject. It's apparent she has absolutely no idea what she's talking about. How many calls centers are running Asterisk
and SER today? Plenty! I really expected more from LJ.

SER and Asterisk

Anonymous's picture

I cannot tell you which VoIP company I work for (not Vonage) but I can assure you that Linux, SER and Asterisk are a VERY large part of our infrastructure. Now if we can get rid of the Solaris and the Windows, we will be really able to take off.

Bad article

Anonymous's picture

I agree. Not only is it usless its confusing. She mentions gnomemeeting as being H323 only in one part then goes on to mention that its both H323 and SIP, she moves between the old and new name where she should use the new name. I'm also not aware that iChat uses SIP, nor does Microsoft Messenger (the free version) but the Live Communications server/client does but isn't free.

Ekiga no longer uses openh323 but rather OPAL and she mentions all the testing was done on Fedora. If that was the case you don't need to actually worry about dependancies as the OS deals with that. And by using Fedora why in the kphone article mention installing it using Synaptics on Ubuntu?

In general a disapointing article. While VoIP isn't the easist to setup most distros comes with the hard work done.

SJPhone is also good, much

Anonymous's picture

SJPhone is also good, much simpler interface (but just as featureful) as X-Lite:


Skibum - Derek Jacobs - CounterPath Support's picture

Hello Machtelt

I just thought you should know that it is possible to do IP to IP calling with X-Lite. Here are some brief instrictions:

Make a new SIP Proxy with the following details

Enabled: Yes
Display name: Harry (example)
Username: harry (example)
SIP Proxy: Your local IP
Direct Dial IP: Yes

Leave everything else alone.

Calling is as follows:


Gizmo Project from SIPphone

Anonymous's picture

I'm suprised you didn't review Gizmo (free download from SIPphone).

Because SIPphone was started by Michael Robertson, founder of Linspire (popular desktop Linux distro), he has always made sure Gizmo worked on Linux. It's certainly, in my view, the strongest free VOIP client out there, particularly for Linux, and offers both basic free service, and the option for advanced, paid-for services.


And what about OpenWengo?

Anonymous's picture

With the GPL code, SIP audio, h263 video, Jabber text and alike Skype/Gizmo features (call out, call in), this application could be a real challange for the other ones. As a right now you can test the 'classic' version while 'NG' (next generation) is under heave developement.
Have look at WengoPhoneNg Overview.

Thats right....Gizmo is

Chandra's picture

Thats right....Gizmo is working much better than sucks too much of RAM and also it doesnt co-operate well with other sound-applications....Gizmo sounds best for linux.

Gizmo and Twinkle

Hans's picture

I second the recommendation of gizmo. Gizmo is not only a decent sip softphone, but it also provides the same services Skype does, without being evil. Another great linux sip softphone is Twinkle.


JID's picture

Sipphone does allow access Ma Bell system for a small fee.
It is my main long distance at the moment.

Openwengo is the best GPL

Anonymous's picture

Openwengo is the best GPL VOIP client with lot features including firefox plugin :) Linux/Mac/Windows

OpenWengo is not the best GPL

Anonymous's picture

The best GPL client on Linux is from far Ekiga. Sorry to disappoint you, but I tried OpenWengo NG on Linux, and it was a big deception for me.

Go Ekiga!

VOIP : Compatibility and Choice is what End-Users Crave for?

Anonymous's picture

I will first of all congratulate the writer for pointing out some facts about VOIP and it application and choice of client software for the End-User.

Yes, VOIP has matured to a larger extend than this article shread light on, but for a new or average linux user who has head about something new called VOIP that all of his friends are using, we certainly do not want to turn them away from buzzing words and unnecesary jargons.

The truth is Skype on Linux is unstable and I have had similar experience with Skype as outline by the author. In addition, I believe what most Linux users as well as programmers are concerned about is the proprietary nature of the skype protocol. We End-Users of today crave for choice. I want to be able to use a Linux machine and be able to communicate with another user using a Mac, Windows, Linux or whatever they opt for. Ekiga, allows linux users to make voip calls to MSN users. This is a victory in itself considering the fuss and excuses windows user make about the switch to linux.

If there was a standardize protocol, then both open source and proprietary source software manufactures could make their product to work with clients of different platforms. I believe this is what the article indirectly was pointing out.

I have used Skype on windows and it's excellent. It provides encrypting of commucation etc. But what is the use when users don't have a real choice of using whatever protocol they desire?

Cisco is in the process of making some of their product compatible with SIP, which is great. Why can't Skyp do the same? Think about he future, will ya?

Re: "Skype on Linux is unstable..."

Sare Okirom's picture

I've been using Skype on Linux (Mandrake 10.1) for over a year now and never had a single problem. My daughter has used Skype on Mandrake 10.0 and 10.2 for more then one and a half year and never experienced a problem either.