Hardware Reference
In-Depth Information
Setting up Linphone
With our
pi
user account up and ready to go, let's proceed to set up Linphone:
1.
Linphone does actually have a graphical user interface, but we'll specify
that we want the command-line only client:
pi@raspberrypi ~ $ sudo apt-get install linphone-nogtk
2. Now we fire up the Linphone command-line client:
pi@raspberrypi ~ $ linphonec
3. You will immediately receive a warning that reads:
Warning: Could not start udp transport on port 5060, maybe this
port is already used.
That is, in fact, exactly what is happening. The standard communication
channel for the SIP protocol is UDP port 5060, and it's already in use by our
SIP Witch server. Let's tell Linphone to use port 5062 with this command:
linphonec> ports sip 5062
4.
Next we'll want to set up our microphone. Use these three commands to list,
show, and select what audio device to use for phone calls:
linphonec> soundcard list
linphonec> soundcard show
linphonec> soundcard use [number]
5.
For the softphone to perform reasonably well on the Pi, we'll want to make
adjustments to the list of codecs that Linphone will try to use. The job of a
codec is to compress audio as much as possible while retaining high quality.
This is a very CPU-intensive process, which is why we want to use the codec
with the least amount of CPU load on the Pi, namely,
PCMU
or
PCMA
.
Use the following command to list all currently supported codecs:
linphonec> codec list
Now use this command to disable all codecs that are not PCMU or PCMA:
linphonec> codec disable [number]
6.
It's time to register our softphone to the SIP Witch server. Use the following
command but replace
[IP address]
with the IP address of your Pi and
[password]
with the SIP password you set earlier for the
pi
user:
linphonec> register sip:pi@[IP address] sip:[IP address]
[password]
