Is Linux Voice over IP Ready?
Prior to experimenting with VoIP applications, you probably will have to use a bit of trial and error to find settings that are comfortable for you. Make sure that you can record and play a sample of your own voice before you start, as the VoIP programs also will use the recording function of your hardware. Activate it in the volume control application that comes with your distribution.
Linux generally has two types of sound architecture: the older Open Sound System or OSS, which works with every UNIX-like system, and the newer Advanced Linux Sound Architecture or ALSA, which has better support for Linux, as the name indicates. One application may support OSS and another, ALSA. When you have a choice, we advise you to select the use ALSA option in VoIP programs. Select ALSA or OSS settings for sound and recording levels accordingly in your distribution's volume control panel.
We tested four applications, based on popularity. We tested all of them on Fedora Linux.
Installation: use the package manager from Fedora. Alternatively, download Debian, Mandrake or Red Hat packages. Ekiga requires the pwlib, OpenH323 and libavc1394 packages.
Getting started—registration: the application shows up in the menus as Video Conferencing. We experienced GConf errors the first time we used it. The solution to that problem is described in the GnomeMeeting FAQ. Once we solved that problem, we could get started with the First Time Configuration Druid.
You can register in the general GnomeMeeting users directory (a telephone book on a central server) or skip this step. My audio devices were recognized automatically, and it was easy to select the headset. You don't need to know the device names of your hardware. For beginning users, it is a great relief not having to worry about /dev/dsp1 and those sorts of names. As shown in Figure 2, all applicable devices can be neatly selected from a list.
Presumably, your machine needs to be configured as an LDAP client (Lightweight Directory Access Protocol, or Active Directory on MS Windows) in order to be able to contact the central GnomeMeeting directory. Lacking that, you need to know the hostname or host IP address and user names of the people you want to call. If you don't use LDAP, you will receive error messages when you try to call someone, even if you can make a successful call.
Impressions: at first there was quite some noise on the connection, even when calling another host in the same subnet, but we could minimize the noise by adjusting the audio volume. There is a mute button for suspending and resuming audio transmission. Luckily, the system with URLs to contact people is well documented in the help files. The application itself doesn't make it easy to use.
Download using your favorite system tool, such as Synaptics on Ubuntu.
Installation: the package manager does the installation for you. You also can download RPM packages and install them using your distribution's tools. After the installation is finished, the KPhone selection turns up in the application menus.
Getting started: your own address is displayed in the little KPhone window, which makes it easy to exchange with other users. It also serves as an example for connecting with other users.
The phone book in this application is easy to use. In the most basic case, simply let others call you, and received and missed caller IDs will show up in the phone book automatically.
Impressions: KPhone has a very sober interface, which makes it easy to use and configure the program.
At one time, I obviously must have configured the wrong audio device while trying to configure KPhone to use my USB headset instead of the built-in speakers and microphone on my laptop. There is no list from which to choose audio devices; this was rather frustrating. KPhone also segfaulted on me a couple of times, even after it had worked fine earlier. I could not get my USB headset to work. Admittedly, I did not use the latest version. Newer versions, which need to be compiled from source on many systems, at the time of this writing, are reported to work better and have much improved sound quality. KPhone has matured a lot in the newest releases and probably will become even more popular than it is already as binary packages are made available.
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